This was disabled during the merge of the initial pull request, PR 630
as this "limits the port to 16bit color precision, i.e. preventing it
from coping with engines like Wintermute, and Sword25.".
The intent was to replace this with GLSL based scalers, and thus to
avoid switching around and confusing users this was disabled.
However, since the GLSL solution has not been implemented after 2 years,
and users are asking for this feature on IOS7, am enabling this for now.
This can always be replaced in future with a GLSL based solution if a
motivated developer provides a patch.
