Exiting edit mode hides the HTML source view.
Removes the editor's keyboard observer for some notifications.
Merge pull request #334 from wordpress-mobile/issue/keyboard-listener-not-being-removed

Removes the editor's keyboard observer for some notifications.
Merge pull request #333 from wordpress-mobile/issue/128-sticky-html-view

Exiting edit mode hides the HTML source view.
Merge branch 'release/0.2.3' of github.com:wordpress-mobile/WordPress-iOS-Editor into issue/154-html-styling

# By Diego Rey Mendez
# Via Diego Rey Mendez
* 'release/0.2.3' of github.com:wordpress-mobile/WordPress-iOS-Editor:
  Removes the editor's keyboard observer for some notifications.
  Exiting edit mode hides the HTML source view.
Busted up a big method.