Bug#493106: New environment variables (for gfxmode and background path and other)

[Felix Zielcke]

tag 493106 + fixed-upstream
retitle 493106 provide support for resolution in GFXMODE variable
thanks

My GFXMODE patch is now commited upstream, we now only need to comment
this now on /etc/default/grub in our Debian package.
Upstream doestn't have an example /etc/default.grub

For the background image case please see 495754 and 495282

For the 3rd suggestion of you:
There's /etc/grub.d/40_custom which is an example how to add custom
static content to grub.cfg