Trim trailing whitespace.
Enable JSHint's trailing check.
Merge branch 'whitespace' of github.com:XhmikosR/less.js into 2_0_0

Conflicts:
	lib/less/functions.js
	lib/less/index.js
	lib/less/tree/anonymous.js
	lib/less/tree/media.js
	lib/less/tree/mixin.js
fix trailing whitespace