add call to finish() to return to list of conversations at end of "handleArchiveThread()" (matching behavior to "handleDeleteThread()")
re-order menu options in "conversation.xml" to put Archive option above Delete
add "archive" icons
add "unarchive" / "move to inbox" functionality. still no dynamic selection of whether to show "move to inbox" or "archive" buttons (depending on whether conversation is currently in inbox or archived).