adding lines under filters.new

adding filters.new.lower_title_with_count and lower_title
Pass sprockets context and environment to Sass::Engine.
Always use DiscourseSassImporter, add optional sprockets deps tracking.
BUGFIX: share pop-up wasn't properly positioned when activated using keyboard
Get rid of plugins.css, inject it using DiscourseSassImporter.
FIX: Markdown javascript error with certain formatting.
FIX: If there is an invalid URI in the import, don't throw an error
REFACTOR: poll mailbox specs
Add back onebox support for flash video
Add subcategory badge to digest emails
Upgrade Onebox gem to get many new fixes
Remove unused SiteSetting
Adds a Site Setting to whitelist onebox domains
Merge pull request #2244 from vikhyat/css-import

Site Customization @import fixes
Safari 5.1 apparently, so fine
don't need the external link glyph in summary now
FEATURE: display unpinned state, allow unpinning by clicking on pin
de-bluing some non-links
Merge remote-tracking branch 'upstream/master'
modifying some styles for the new pin/unpin feature