proposed removal of GR_UnixGraphics and XAP_UnixGnomePrintGraphics

I would like to remove the old GR_UnixGraphics class from HEAD; it's
sole purpose is now to be a base class for GR_UnixPangoGraphics, and it
carries with itself loft of old baggage (like the XAP_UnixFontManager
and friends).

Furthermore, without GR_UnixGraphics there is no need for the
XAP_UnixGnomePrintGraphics class, as the relevant parts of it can be
moved directly into the GR_UnixPangoPrintGraphics class, and we can then
finally ditch the remnants of the old PostScript driver that the
XAP_UnixGnomePrintGraphics still depends on.

Attached for review/testing/comments are patches for HEAD abi and
abiword-plugins to do that.

Tomas