fix NO_PREREQ_INSTALL
Merge pull request #6024 from edx/clytwynec/fix_no_prereq_install

fix NO_PREREQ_INSTALL
Add grunt and update package.json
Start generating css files for LMS

Still using ruby sass for now, waiting for lbsass.
adding most of the lms files to the grunt task
Create CSS files for the LMS

Add LMS task to run both 'sass' and 'concat' tasks.
Add time-grunt to display how long tasks take to run.
Add LMS clean task to remove generated files
 Adding grunt-sass library
Change neat version to 1.5.1
Remove neat and bourbon from the repository
Add grunt lms watch task
Adding a studio task with subtasks for sass, clean and concat
Add missing files to the lms build
Move bi-app-ltr import below bourbon

Bourbon’s margin mixin was overriding bi-app-ltr’s
Fix bourbon path in static content script
Stop compiling Sass in the pavelib
Update Gruntfile to include configuration

Add studio watch task.
Create base, :dev and :dist tasks for each environment.
Add cssmin tasks for both lms and studio
Install bi-app using bower

Remove from both applications static files.
Update missing trl/ltr