Feature/will/ci lettuce tests

Resolved conflict with changes to Rakefile in master

Conflicts:
	rakefile

Merge branch 'feature/will/ci-lettuce-tests' of https://github.com/edx/edx-platform into feature/will/ci-lettuce-tests

Install python prereqs before trying to run django or install requiremen...

Studio - Resolving incorrect Sans Serif Sass Variable Definition

studio - fixes Sass variable defintion to ensure the older -serif references the proper new -sans-serif variable

Feature/cale/maintain dev environment

Make the externally facing asset watch commands wait for user intervention, and add internal tasks that only run as long as the rake process

Move Mysql and scipi to requirements/post.txt, because they require the contents of requirements.txt to be completely installed

Add documentation of xmodule template files

Allow django liveserver to use larger port range

Make gcli commands flexible around org and repo name

Use one virtualenv for each parallel build process