Recursively add child content (Bootstrap <v3.1) to collection
Add generation offset to cells (aka replies)
prevent content body label from overlapping bottom cell border
Move content filtering into model object (LFSContentCollection)

Motivation: This lets us apply the same filtering to both top- and child-level content.
Pass placeholder image to detail view
Fix a case of subtitle (Twitter handle) not being offset

For replies to other pieces of content, fix a layout bug where
left offset for subtitle view would not be updated during cell configure
Handle Twitter status URLs

Also make hash-bangs optional for Twitter app redirects.
Reply order now correct (but inverse)

Newer responses are shown above. This will be fixed in the next commit.
Sort content by date

Previously it was sorted by eventId, which is wrong...
Merge pull request #42 from Livefyre/dev

Add threading to content collection