Create a custom view containing the bottons below MVF
(delete, move, reply, etc) and let MVF own this.
These buttons used to be owned by the XL activity itself, because
the UI for these commands will most likely be totally different
from the tablet UI, so the fragment having them looked wrong.
However, this made it harder to make changes suggested by the latest
mock, such as "put reply/forward in the message header".
I think the buttons are semantically part of the message view anyway,
so the fragment owning UI for these commands is probably the way to go.
(And let's worry about the phone UI later.)
Reason for the use of a custom view is that it will make it easier
to make non-trivial UI changes, e.g. "combine reply, reply-all and
forward and make it dropdown."
Also removed obsolete TODOs from MessageListXL.
Change-Id: Ibf93f4c70fe07bdbbe33d2adb6bbd2b96812830d
0435a0775e