Some (easy) cleanups as suggested from @daira.

Thanks!

src/bls12_381/ec.rs

@@ -166,6 +166,7 @@ macro_rules! curve_impl {
             fn into_projective(&self) -> $projective {
                 (*self).into()
             }
+
         }
 
         impl Rand for $projective {

src/bls12_381/fq.rs

@@ -814,6 +814,7 @@ impl SqrtField for Fq {
     fn legendre(&self) -> ::LegendreSymbol {
         use ::LegendreSymbol::*;
 
+        // s = self^((q - 1) // 2)
         let s = self.pow([0xdcff7fffffffd555, 0xf55ffff58a9ffff, 0xb39869507b587b12,
                           0xb23ba5c279c2895f, 0x258dd3db21a5d66b, 0xd0088f51cbff34d]);
         if s == Fq::zero() { Zero }

src/bls12_381/fq2.rs

@@ -432,6 +432,7 @@ fn test_fq2_sqrt() {
 fn test_fq2_legendre() {
     use ::LegendreSymbol::*;
 
+    assert_eq!(Zero, Fq2::zero().legendre());
     // i^2 = -1
     let mut m1 = Fq2::one();
     m1.negate();

src/lib.rs

@@ -327,7 +327,7 @@ pub trait Field: Sized +
 /// This trait represents an element of a field that has a square root operation described for it.
 pub trait SqrtField: Field
 {
-    /// Returns the legendre symbol of the field element.
+    /// Returns the Legendre symbol of the field element.
     fn legendre(&self) -> LegendreSymbol;
 
     /// Returns the square root of the field element, if it is