Keyframes breaks Safari 10.11 and iOS9 beta

[davipt]

Duplicate from #139 and #129, just to make clear that

1. Safari 10.11 and iOS9 beta are breaking with this
2. the issue is not the extra semicolon at the last line (@Keyframe), but the lack of the "}" closing it at the same line.

So I added a closing "}", which means I need to create a dummy line to reopen "{".

[herrmannplatz]

Would be nice to have this fix in, as it also breaks code quality tools like csscss.

[twobit]

+1 causing problems for us too.

[IgorLesnevskiy]

+1 head broke yesterday

[mboudreau]

This has been fixed in 4.0.1.