Deal with nil once at the beginning of NSBubbleData-initWithText.
Make UIBubbleHeaderTableViewCell ARC-safe.
Extract inline integers into named constants.
Use more of the incoming keyboard user info to animate.
A little flair: scroll to the bottom when adding a message.
Rename UIBubbleTableViewDataSource-rowsForBubbleTable.

Now, it's -numberOfRowsForBubbleTableView, which
mirrors the equivalent UITableView selector.
Do less in the manual reference counting blocks.
Extract dataSource <-> bubbleDataSource logic as an adapter.

This allows user view controllers to act as a real
delegate for UIBubbleTableView (eg., previously,
scroll events were not accessible to UIBubbleTableView
view controllers).

Also set project's class prefix to 'SG' and org to
'Stex Group'.
Access bubbleTable via property accessors.
Add a little more flair: animate origin instead of height.

This keeps the most recent messages in view while composing.

Also, dismiss keyboard when scrolling the bubble table.
Assign bubbleTableView delegate via xib wiring.
Allow setting background color and separator style via UIAppearance.

Background color no longer has a default value
(previously was clear). Default separator style (none)
overrides any XIB setting.