Fix build for rustc 0.13.0-nightly (99d6956c3 2014-12-18 20:32:07 +0000)

RFC 378 has landed in rust-nightly. Thus macros are always parsed as
expressions and since we use a lot of macros as statements we need to
add semicolons to all of those macro invocations.

fixes #25
Merge branch 'master' into box_inplace