Fix packaging
Merge trunk
map U_ON_SCREEN_KEYBOARD_ROLE to mir_surface_type_inputmethod
Merge relevant parts of Daniel d'Andrada's work lp:~dandrader/platform-api/mir-with-packaging-inputmethod
As Mir has specific inputmethod surface type, use that instead of OSK role. Remove role property for now
Restore default deconstructor
Add "state" property to Window, implement show/hide/fullscreen functions
Remove the added "type" property, just map "role" to mir surface type.
Merge trunk
Enable OSK window role, which ties into Mir's OSK surface type. Also add "state" property to Window, and this implement show/hide/fullscreen functions using Mir's surface state API.

Approved by PS Jenkins bot.