In Control::setFont the passed font and not the font from the
SWTFontProvider is used. This has only an effect when the
ScaledFontRegistry is used and a font is passed, that does not match the
current zoom of the control.

Contributes to
https://github.com/eclipse-platform/eclipse.platform.swt/issues/62
and https://github.com/eclipse-platform/eclipse.platform.swt/issues/127