- Heavily modified patch #1214784: "Disable overlay scaling"

- Eriktorbjorn's patch from same tracker item for scaling sword1/2 cutscenes
  is applied as is. It lacks resolution switch on-the-fly.
- GUI widgets are repositioned on the fly and use most space, even aspect
  ratio corrected screen is used without scaling
- Heavy tesing is required, but works for me in all cases except for bug
  #1483272: "GUI: SCUMM pause dialog breaks upon scaler switch" which needs more
  work.
- I probavly broke some backend or two

svn-id: r22505

backends/sdl/sdl.cpp

@@ -175,7 +175,7 @@ OSystem_SDL::OSystem_SDL()
 #endif
 	_hwscreen(0), _screen(0), _screenWidth(0), _screenHeight(0),
 	_tmpscreen(0), _overlayWidth(0), _overlayHeight(0),
-	_overlayVisible(false), _overlayScale(1),
+	_overlayVisible(false),
 	_overlayscreen(0), _tmpscreen2(0),
 	_samplesPerSec(0),
 	_cdrom(0), _scalerProc(0), _modeChanged(false), _dirtyChecksums(0),