Register qt.conf in Qt resource system to override the Qt builtins

Register qt.conf in Qt resource system to override the built-in
configuration variables if there is no default qt.conf in
executable folder and qt.conf was not already registered in Qt
resource system

Change-Id: Ibed9f9e791dab575ef26bc54b351e5f5d4870542
Reviewed-by: John Ehresman <jpe@wingware.com>