Re-apply gitfs patches to live-boot

This basically applies:

	git diff 042cac9 2ee06be --  lib/live/boot* | sudo patch -p1

However, the filenames were changed, so the new files needed to be
given to the patch prompts.

This commit breaks the boot, due to some actual changes in live-boot. This will
be fixed in the next commit.

Conflicts:
	lib/live/boot/9990-misc-helpers.sh
Update git-fs to work with newer live-boot

The overlay script in live-boot got changed subtly, so our git-fs additions
were now setting the wrong variable. This makes booting work again.
Replay commits as @matthijskooijman suggested :-)
https://github.com/Webconverger/webc/issues/198#issuecomment-55237713