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
Added info about Roowifi ext_lib to readme
just some fix attempts
fixed POIs position mapping back to a working one
First steps of tracing
updateLoc function to mapQGraphicsView. Unfinished
map support for location, direction and tracing
Currently all the related functionality is in updateLoc and only
a single roomba is supported. Not tested with real input.
rebranched and added stuff for calling updateLoc
fixing weird differences with local and remote branches
Merge branch 'JuhaniJ/jj_test' of https://github.com/joonaspessi/rotfl into jj_test

Conflicts:
	src/ui/mainwindow.cpp
	src/ui/mainwindow.h
	src/ui/mainwindow.ui
	src/ui/mapQGraphicsView.h