Implement JS minification, concatenation, and mangling

Probably use Slimit for this:
http://slimit.readthedocs.org/

Also study what the Rails asset pipeline does:
http://guides.rubyonrails.org/asset_pipeline.html

Start by reading the Slimit documentation and the Rails asset pipeline guide linked in the issue. Define the project entry points and expected behavior for JavaScript minification, concatenation, and mangling before implementation; done means all three operations work together as intended.

Written by the indexing model from the issue text.