UI change: MassageCompose

Basic changes for the new UI.  At this point we don't know what the new phone
UI will look like, so I didn't bother trying to preserve the old behavior on
the phone UI.  The changes will affect both the phone UI and the tablet UI.

- Send, Save Draft, and Discard are now action bar commands.
- Add CC/BCC and Add Attachment are now regular buttons.
- Activity title changed to "Compose"
- Some string changes per new wireframe

Further changes (actual layout changes for the latest wireframe) should be made
only for the xlarge layout.

Change-Id: I68c9c37dfdca6736b1e35053e7f196800fcfce2e
2 files changed