Add Less v2 as a dependency

[jfsiii]

This is a Less plugin, so Less is required. Include it as a dependency.

Whitespace changes are a result of npm install --save. Also removed "autoprefixer" from keywords.

[lukeapage]

Actually less is only a dev dependency..(for tests only) thanks for noticing the keyword.
I don't want to add the less dependency even in dev till v2 (stable, not a beta) is released, because it stop people install ing this for use with a beta.