Add LiveScript support.
Add LESS support (.less)

Cheating slightly as it uses the CSS lexer, as pygments currently does
not have a dedicated less lexer. But I figure language recognition and
90% percent correct syntax highlighting is better than neither.
Merge pull request #344 from BPScott/add-less

Add LESS support (.less)
Change LiveScript colour.
Merge pull request #324 from paulmillr/topics/livescript

Add LiveScript support.