Wasn't needed and prevented an extra item from being shown
on smaller screen devices.
Fixes b/5521012 Fix padding in the folders list
Change-Id: Ifc940d44b9a8a0a0f0f9d04fc1958f4810adcdbe
* Moves all list-related implementation to new MailboxListFragment
* One item that remains to be done is to remove the dependency on the
activity for handling context menu (longpress) in the list.
Change-Id: I7b5769d9d81fb685cf480de3d3e18b4e1c078f2d
