- replaced gofmt expression formatting algorithm with
  rsc's algorithm
- applied gofmt -w misc src
- partial CL (last chunk)

R=rsc, r
http://go/go-review/1024041
diff --git a/src/pkg/math/atan2.go b/src/pkg/math/atan2.go
index 95226b9..7165c53 100644
--- a/src/pkg/math/atan2.go
+++ b/src/pkg/math/atan2.go
@@ -12,16 +12,16 @@
 	// Determine the quadrant and call atan.
 	if x+y == x {
 		if x >= 0 {
-			return Pi/2
+			return Pi / 2
 		}
 		return -Pi / 2;
 	}
-	q := Atan(x/y);
+	q := Atan(x / y);
 	if y < 0 {
 		if q <= 0 {
-			return q+Pi
+			return q + Pi
 		}
-		return q-Pi;
+		return q - Pi;
 	}
 	return q;
 }