BUG:1904421
* update READ/UNREAD indications
** don't change color chip
** change background color
* Change Date
* Change the position of attachement icon
* Change menu icon for folder
* Final list of options while normal mailbox is shown
* New list of options while smart folder is shown
* Correct lists of context options for drafts, outbox, trash, and
everywhere else (full list)
* Enable reply, reply all, and forward
TODO: needs a better icon for menu->folders
Resolves bug 1904421 items 4a, 4b, 5a
Resolves bug 2078092
* Add MessageList Activity class and Manifest entry
* Add appropriate layouts, views, etc.
* Wire into FolderMessageList
Lots to do, but this gives us a useable screen.