Make actions shown in message view menu configurable

[Issue 5889](https://code.google.com/p/k9mail/issues/detail?id=5889) and [issue 5850](https://code.google.com/p/k9mail/issues/detail?id=5850) are about the Archive button not being directly available in the message view. This branch makes all "Refile" actions available as direct menu items in the message view, configurable via an option in the Global Settings.

One thing I am still unhappy about is that the same icon is currently used for the copy and move actions (`iconActionMoveOrCopy`). Maybe we could use the copy icon from the system text selection menu?