Adds info about installing coffee for node

The page is titled "Installing Coffeescript", yet only node + jasmine was handled. Coffee doesn't come by default, so this could cause confusion for less experienced users
Merge pull request #1547 from naps62/master

Adds info about installing coffee for node
Add beginning of acceptance tests for redesign
Merge pull request #1551 from jetaggart/master

Add beginning of acceptance tests for redesign
Update contributing guide
remove sass-cache, ignore more rubymine
Merge pull request #1557 from jetaggart/master

remove sass-cache, ignore more rubymine
Create looks backend
Write to looks table on viewing submission
Add page that lists recently viewed exercises
Add link to recently viewed exercises page
Make all paths relative to root
Don't change development database string
Merge pull request #1558 from jetaggart/master

Change all paths to be relative to root
Implement notifications page
Delete notification app
Delete backbone
Add task to create alerts about notifications
Update about page
Merge branch 'notifications'