MMS: Enter key action

Provide an option to force newline (instead of send).
For some keyboards (eg. SwiftKey) the shift+enter solution doesn't work.

PS 10: Updated localisation and order.
PS 11: Bugfix. Works nice now.

Change-Id: I16c16df9e94fd334785e830091be44a5237db48a
merge changes from Omni 4.4 into local branch