Add ports for wxgtk and wxgtk-contrib common files (includes, other data files).
Allow different flavors of wxWindows library (gtk, gtk2, gtk2+unicode)
to coexist.
Patches to fix compiling -contrib in Unicode mode are taken
from wxWindows CVS.
wxgtk-devel is master port for all wxgtk ports (will be moved to wxgtk soon).
wxgtk-common and wxgtk-contrib-common ports respectively.
Assign maintainership of all wxgtk ports to myself for a while
to catch errors on bento.
