Better refresh and CGLayer

With the help of Paveljanik, I was able to get better screen refresh !

For now, I added immediate zone refresh for teh zone where I draw text in salatslayout.

I added two methods to AquaSalGraphics : RefreshWindow (ask to refresh entire window -> slow) and RefreshRect (ask to refresh a zone)

The results are good when text typing.

I still have not been able to reproduce my old configuration where cursor was visible and moving real time between chars... but I guess I'm not so far from a good surprise !

I also reintroduced the CGLayer, as I better understood the roel of mrBitmapContext wit hteh help of Pavel.
I'll have to fix some code inorder the mrCGLayerContext to be initialized on time when used by methods using mrBitmapContext.

I need a some time to do that, but I'm confident...

I need some explanation on when the CGContextTranslateCTM is preserved or lost, because I have funny behaviour :
1) everything is drawn correctly with CGLayer
2) a second after (refresh ?) everything is upside down (in fact th text is still in the right sense but lines are drawn in invert order)
.... funny and weird ;-)

To be continued