@0x/types: Add FillResults, MatchedFillResults, and

`BatchMatchedFillResults` types.
`@0x/contracts-utils`: Add reference functions for `SafeMath`.
`@0x/contracts-exchange-libs`: Add reference functions for `LibMath` and
`LibFillResults`.
`@0x/contracts-test-utils`: Move `*FillResults` types to `@0x/types`.
`@0x/contracts-test-utils`: Add `log_utils.ts`.
`@0x/contracts-test-utils`: Add `hexRandom()` to `hex_utils.ts`.
`@0x/contracts-test-utils`: Add the contstants: `MAX_UINT256`,
`ADDRESS_LENGTH`.

contracts/test-utils/src/index.ts

@@ -29,7 +29,6 @@ export { TransactionFactory } from './transaction_factory';
 export { testWithReferenceFuncAsync } from './test_with_reference';
 export { hexConcat, hexRandom } from './hex_utils';
 export {
-    BatchMatchedFillResults,
     BatchMatchOrder,
     ContractName,
     ERC20BalancesByOwner,
@@ -37,10 +36,8 @@ export {
     ERC1155HoldingsByOwner,
     ERC1155NonFungibleHoldingsByOwner,
     ERC721TokenIdsByOwner,
-    FillResults,
     MarketBuyOrders,
     MarketSellOrders,
-    MatchedFillResults,
     OrderInfo,
     OrderStatus,
     Token,