Added text labels to moderation buttons.

Clearer moderation icons.
Added ability for WPContentView to display the date in the 'byView'.
Added a vertically stacked UIButton subclass to use for the moderation buttons.
restored `addActionButton` method back to its original state.
Added alert prompt to be shown when a comment couldn't be moderated.
removed now unused methods from `ContentActionButton`
Adjusted button size back to 48 pixels.
Added 'Un' toggle states for the Trash and Spam buttons.
Added action sheet delete prompt for trashing a comment since it is destructive.

Added error alert prompt if moderation fails in `CommentViewController`
Removed now unused icons.
Use correct name for new spam icon.
Code cleanup: Use `setAccessibilityLabel` method instead of dot notation so the code reads easier.
Removed unnecessary else clause when updating a button's status.
Added `updateStateOfActionButton: toState:` in case we want to set the state of an individual button.
Added an enum for a note's comment actions.
increases width of timeButton
shartens lines over 120 characters
converts tabs to spaces in WPContentView.m
Increased width for `timeButton` only.
Merge branch 'develop' into issue/79-better-comment-moderation-and-icons

Conflicts:
	WordPress/WordPress.xcodeproj/project.pbxproj