Add a Notes tab.
Integrate WYSIHTML5 editor inside the note tab.
Return nothing if a non-existent file is requested through the API.
Read existing notes from the server via the API.
Saving mechanism for notes in place.
Modify the save button if there are unsaved changes and also warn the user if navigating away from chris and the notes are not saved.
Merge branch 'notes_for_all_feeds'