Changes / complexity in splash branding

* The new splash code is simple.
	+ we only load .png files
	+ we look in program/ for 'about.png' and 'intro.png'
	+ we load locale-sensitive images
	+ we install brazilian variants for BrOffice

* The new 'shell' code is simple too
	+ it looks in program/shell for it's artwork
	+ I added a README.txt to default_images to explain the code locations

* The new unx quick-starter needs work:
	+ needs to load .png files ...
	+ ergo has to be enabled per distro, not in generic builds
