Implement move-to-trash for IMAP and POP3.

* Define new message-loaded state "FLAG_LOADED_DELETED" (used only for
   POP3, which needs to write sentinel messages that are not displayed.)
* Also renamed the other flags to make the naming more consistent.
* Tweak MessageList query generation to inhibit display of deleted
    message sentinels, and MessagingController won't try to resync them.
* Clean up implementation of Controller.deleteMessage()
* Add support for move to trash to MessagingController.  This operates
    in three primary modes:
  * POP3 local delete (no server-side interaction)
  * POP3 server delete
  * IMAP server delete (and copy to IMAP trash mailbox)
* Add missing implementation in provider to delete all of the attachments
    for a given message
* Fix progress reporting in activities (the test for error vs. progress
    was inverted, which caused progress indicators to keep spinning
    after errors.)
* Fix broken account settings UI (POP3 delete policy was not persisting)

Addresses bug 2097409

TODO delete from trash / empty trash

Change-Id: I00188e6dc2093823106e009f35b68c760227c9e6
1 file changed