Move the stylesheets out stylesheets/libs.

This is the first step in better organizing the stylesheets to be broken apart
into separate files to be more digestible.
Split apart the cookbooks stylesheet.

Create smaller files logically named by the areas of Cookbooks they pertain to.
Sprockets requires_tree for the cookbooks styles, meaning that any file added to
the folder will automatically be included.
Remove empty globalcolumn stylesheet.
Move the user styles into a directory.
Increase the capybara timeout.
Merge pull request #391 from opscode/split_up_stylesheets

Split up the Supermarket stylesheets to be more digestible
Increment web_download_count instead of download_count
The API file download URL is distinct from the web URL
Track API download counts in the API download action
API downloads redirect directly to a tarball
The SegmentIO agent keeps track of the last event tracked
Test that the API downloads are tracked in SegmentIO
Test that web downloads are tracked in SegmentIO
Encapsulate aggregate download statistics
Compute a cookbook version's download count in-memory
Compute a cookbook's download count in-memory
Order cookbooks by their segmented download counts
Remove the now-unused download_count columns
Adjust the bottom margin for tab dds.

This fixes the style issue where a border-bottom was still displayed on active
tabs.
Merge pull request #392 from opscode/fix_active_tab_style

Adjust the bottom margin for tab dds.