Bug#543807: customizing /etc/default/grub

[jidanni at jidanni.org]

I am hoping there will be a place where we end users can have some "final words"
local settings that are read in without disturbing the vanilla setup.

We of course would be responsible for seeing apt-listchanges News items
about important changes.

However it seems that if we change e.g., GRUB_CMDLINE_LINUX_DEFAULT,
upon the next run, that is detected, and then is stuck into
/etc/default/grub, thus one cannot avoid changing the vanilla setup.