Improve spacing around binary operators

The spaces around binary operators are now sometimes omitted (can be
disabled with the forceSpaceAroundBinaryOp option). For details on when
this happens, see #99 and the documentation for
useSpacesAroundBinaryOp().

Closes #99.
Update test samples for #99
Format source code / update for #99
Add test for #99
Merge branch '99'