Bugfix: clear content before getting bootstrap info

This way we don’t duplicate the content of a collection.

Additionally, move some code from UITableView into
UITableViewCell. This way we can properly set the delegate
of attributedTextContextView to nil when cell is deallocated.
Use transparent bars on iOS7 only

Also make textfield background color white.
Do not use “Write comment” bar button

Per Jordan S., only use a text field in the toolbar.
Mod appearance of UITextField for iOS6

Subclass UITextField as LFSTextField. This allows us to have
a text field control where we can (a) specify insets, (b) have
arbitrarily rounded corners on iOS6.
Merge pull request #3 from Livefyre/dev

Dev