Added a method KisCanvas::setMonitorProfile()

This method sets the monitor profile of the canvas and updates
all its caches in a proper thread-safe way.

What is *not* done:
1) Handling of KisCanvas2::Provate::monitorProfile/renderingIntent.
They are currently set in quite a random way in different methods.
There should be some order in it.
2) Handling of the rendering intent in the openGL canvas, although a
variable was added for it.