Add methods for blocking a site and deleting its posts.
Add a menu button to the attribution view.
Wires up the content view to interact with the attribution menu
Wires up the call to block a site from the reader.

Displays an UIActionSheet with the block option.
Removes an NSLog and an unnecessary call to set `shouldShowActions` on the post view.
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issues/1978-block-site
Check success value in response from server.
Better presentation for the iPad
Added some logging for deleting posts.
Miscellaneous changes from feedback.

Block button should be destructive.
Only show the attribution menu for freshly pressed and tags.  Not other list type topics.
Removes the single quotes from the site title in the block feature's action sheet.
Adding an undo feature when blocking a site.
Style's the blocked site message.

Reverts back to the longer button title for the action sheet.
Shuffles some code for better organization.
Dismiss actionsheet if content changes.
Merge branch 'develop' of github.com:wordpress-mobile/WordPress-iOS into issues/1978-block-site

Conflicts:
	WordPress/Classes/ViewRelated/Reader/ReaderPostsViewController.m
	WordPress/Classes/ViewRelated/Views/WPContentAttributionView.m
	WordPress/Classes/ViewRelated/Views/WPContentViewBase.m
Rollback datamodel change.
Reimplement datamodel change with revision.
Just show one blocked cell regardless of the number of posts.

Updates isSiteBlocked property to be required & sets a default value.
Switch from chevron to ellipsis for icon.
Append a protocol if its missing.
Merge pull request #2249 from wordpress-mobile/issues/2242-follow-site-fix

Append a protocol if its missing.
CommentService: Implements REST Helpers