merge feature
Merge branch 'master' of https://github.com/less/less-docs

Conflicts:
	content/features/merge.md
Fix merge error
Merge pull request #34 from seven-phases-max/master

Added placeholders for "Mixins as Functions", "Recursive Mixins / Loops"
first pass on extends (still more todo - see all the todos at the end of file
Merge branch 'master' of https://github.com/less/less-docs
some re-wording as suggested by @seven.phases.max
Add some use-cases for extends
Updated mixins-recursive-loops.md