Quick real-time & Select All

BUG : When calling ModifiedHandler() on Realtime, each window was rendering and therefore calling that function again for nothing. Now we reomove the observer on those renderWindows befor rendering, and put them back after
BUG : The backgroundcolor took a look time changing when switching on "Select All" before colorMapChanged was called each time one window was edited. Now it's called only one time once all the renderWindows are edited.