[Fedora-livecd-list] xz (lzma2) support very likely for 2.6.38

[Bruno Wolff III]

Lougher has made a pull request for xz support (effectively lzma2) for
squashfs for 2.6.38. The merge window closes in about 3 days, so we should
know pretty shortly whether or not this request is accepted, but the odds
look good.

We already have squashfs-tools support ready to go. I'll work on adding
a documentation patch to note xz as an available compression type soon.
Once we have a 2.6.38 kernel in rawhide (assuming the patch set gets pulled)
I like to switch the default to using xz instead of gzip for livecd-creator.
If we find problems we can switch back easily, but I'd like to get testing
going earlier rather than later.