The text rendering is now abstracted into the TextRender abstract class.
Additionally we have now an abstracted cairo rendering class
CairoTextRender which is a subclass of the TextRender class. The
CairoTextRender class is still platform independent and needs to be
subclassed to implement the few platform dependent methods.

You can reuse the cairo based text rendering now by subclassing
CairoTextRender for the platform that you need.

Conflicts:
	vcl/unx/generic/gdi/salgdi.cxx

Change-Id: I8b07e3fe646a81563d308971d30e14a00fd921ad