Added Roowifi external library
Added test buttons to UI for testing the ext lib

Basic Roomba controlling could be done with WASD-directionkeys and
push buttons in the UI.
Added class skeleton RoombaRoowifi
Added basic sensor reading and taken iRoomba interface into use

* Added basic sensor reading over RooWifi from Roomba (temperature+chargelevel)
* Roowifi implementation moved to roombaRoowifi which implements iRoomba interface
* Added and improved buttons and their naming in UI