Removed lingering references to stale terminology ("active pools")

contracts/staking/contracts/src/fees/MixinExchangeFees.sol

@@ -86,7 +86,7 @@ contract MixinExchangeFees is
         IStructs.PoolStats memory poolStats = poolStatsByEpoch[poolId][currentEpoch_];
         IStructs.AggregatedStats memory aggregatedStats = aggregatedStatsByEpoch[currentEpoch_];
 
-        // If the pool was previously inactive in this epoch, initialize it.
+        // Perform some initialization if this is the first protocol fee collected in this epoch.
         if (poolStats.feesCollected == 0) {
             // Compute member and total weighted stake.
             (poolStats.membersStake, poolStats.weightedStake) = _computeMembersAndWeightedStake(poolId, poolStake);
@@ -94,7 +94,7 @@ contract MixinExchangeFees is
             // Increase the total weighted stake.
             aggregatedStats.totalWeightedStake = aggregatedStats.totalWeightedStake.safeAdd(poolStats.weightedStake);
 
-            // Increase the number of active pools.
+            // Increase the number of pools to finalize.
             aggregatedStats.poolsToFinalize = aggregatedStats.poolsToFinalize.safeAdd(1);
 
             // Emit an event so keepers know what pools earned rewards this epoch.
@@ -112,7 +112,7 @@ contract MixinExchangeFees is
         aggregatedStatsByEpoch[currentEpoch_] = aggregatedStats;
     }
 
-    /// @dev Get information on an active staking pool in this epoch.
+    /// @dev Get stats on a staking pool in this epoch.
     /// @param poolId Pool Id to query.
     /// @return PoolStats struct for pool id.
     function getStakingPoolStatsThisEpoch(bytes32 poolId)

contracts/staking/contracts/src/interfaces/IStakingEvents.sol

@@ -43,7 +43,7 @@ interface IStakingEvents {
         address exchangeAddress
     );
 
-    /// @dev Emitted by MixinExchangeFees when a pool will earn rewards.
+    /// @dev Emitted by MixinExchangeFees when a pool starts earning rewards in an epoch.
     /// @param epoch The epoch in which the pool earned rewards.
     /// @param poolId The ID of the pool.
     event StakingPoolEarnedRewardsInEpoch(
@@ -53,10 +53,10 @@ interface IStakingEvents {
 
     /// @dev Emitted by MixinFinalizer when an epoch has ended.
     /// @param epoch The closing epoch.
-    /// @param poolsToFinalize Number of pools to finalize in the closing epoch.
-    /// @param rewardsAvailable Rewards available to all active pools.
-    /// @param totalWeightedStake Total weighted stake across all active pools.
-    /// @param totalFeesCollected Total fees collected across all active pools.
+    /// @param poolsToFinalize Number of pools that earned rewards during `epoch` and must be finalized.
+    /// @param rewardsAvailable Rewards available to all pools that earned rewards during `epoch`.
+    /// @param totalWeightedStake Total weighted stake across all pools that earned rewards during `epoch`.
+    /// @param totalFeesCollected Total fees collected across all pools that earned rewards during `epoch`.
     event EpochEnded(
         uint256 indexed epoch,
         uint256 poolsToFinalize,

contracts/staking/contracts/src/interfaces/IStructs.sol

@@ -29,7 +29,7 @@ interface IStructs {
         uint96 lastSetTimestamp;
     }
 
-    /// @dev Stats for a pool that actively traded.
+    /// @dev Stats for a pool that earned rewards.
     /// @param feesCollected Fees collected in ETH by this pool.
     /// @param weightedStake Amount of weighted stake in the pool.
     /// @param membersStake Amount of non-operator stake in the pool.

contracts/staking/contracts/src/libs/LibCobbDouglas.sol

@@ -33,11 +33,9 @@ library LibCobbDouglas {
     ///         0 <= alphaNumerator / alphaDenominator <= 1
     /// @param totalRewards collected over an epoch.
     /// @param fees Fees attributed to the the staking pool.
-    /// @param totalFees Total fees collected across all active staking pools in
-    ///        the epoch.
+    /// @param totalFees Total fees collected across all pools that earned rewards.
     /// @param stake Stake attributed to the staking pool.
-    /// @param totalStake Total stake across all active staking pools in the
-    ///        epoch.
+    /// @param totalStake Total stake across all pools that earned rewards.
     /// @param alphaNumerator Numerator of `alpha` in the cobb-douglas function.
     /// @param alphaDenominator Denominator of `alpha` in the cobb-douglas
     ///        function.

contracts/staking/contracts/src/stake/MixinStakeBalances.sol

@@ -72,7 +72,7 @@ contract MixinStakeBalances is
 
     /// @dev Returns the total stake for a given staker.
     /// @param staker of stake.
-    /// @return Total active stake for staker.
+    /// @return Total ZRX staked by `staker`.
     function getTotalStake(address staker)
         public
         view

contracts/staking/contracts/src/sys/MixinFinalizer.sol

@@ -35,9 +35,9 @@ contract MixinFinalizer is
     /// @dev Begins a new epoch, preparing the prior one for finalization.
     ///      Throws if not enough time has passed between epochs or if the
     ///      previous epoch was not fully finalized.
-    ///      If there were no active pools in the closing epoch, the epoch
+    ///      If no pools earned rewards in the closing epoch, the epoch
     ///      will be instantly finalized here. Otherwise, `finalizePool()`
-    ///      should be called on each active pool afterwards.
+    ///      should be called on these pools afterward calling this function.
     /// @return poolsToFinalize The number of unfinalized pools.
     function endEpoch()
         external
@@ -80,7 +80,7 @@ contract MixinFinalizer is
         // Advance the epoch. This will revert if not enough time has passed.
         _goToNextEpoch();
 
-        // If there were no active pools, the epoch is already finalized.
+        // If there are no pools to finalize then the epoch is finalized.
         if (aggregatedStats.poolsToFinalize == 0) {
             emit EpochFinalized(closingEpoch, 0, aggregatedStats.rewardsAvailable);
         }
@@ -88,11 +88,11 @@ contract MixinFinalizer is
         return aggregatedStats.poolsToFinalize;
     }
 
-    /// @dev Instantly finalizes a single pool that was active in the previous
+    /// @dev Instantly finalizes a single pool that earned rewards in the previous
     ///      epoch, crediting it rewards for members and withdrawing operator's
     ///      rewards as WETH. This can be called by internal functions that need
     ///      to finalize a pool immediately. Does nothing if the pool is already
-    ///      finalized or was not active in the previous epoch.
+    ///      finalized or did not earn rewards in the previous epoch.
     /// @param poolId The pool ID to finalize.
     function finalizePool(bytes32 poolId)
         external
@@ -107,7 +107,7 @@ contract MixinFinalizer is
             return;
         }
 
-        // Noop if the pool was not active or already finalized (has no fees).
+        // Noop if the pool did not earn rewards or already finalized (has no fees).
         IStructs.PoolStats memory poolStats = poolStatsByEpoch[poolId][prevEpoch];
         if (poolStats.feesCollected == 0) {
             return;
@@ -235,8 +235,7 @@ contract MixinFinalizer is
         view
         returns (uint256 rewards)
     {
-        // There can't be any rewards if the pool was active or if it has
-        // no stake.
+        // There can't be any rewards if the pool did not collect any fees.
         if (poolStats.feesCollected == 0) {
             return rewards;
         }

contracts/staking/contracts/test/TestDelegatorRewards.sol

@@ -94,7 +94,7 @@ contract TestDelegatorRewards is
         currentEpoch += 1;
     }
 
-    /// @dev Create and delegate stake that is active in the current epoch.
+    /// @dev Create and delegate stake to the current epoch.
     ///      Only used to test purportedly unreachable states.
     ///      Also withdraws pending rewards.
     function delegateStakeNow(