Moving/editing lib/README

The old one is no longer relevant; moving it to local/ and editing it to
make clear what should be done.
Sorting dreamhack-exlude.lst

(I'll be editing it in the next commit and this helps make it easier to
tell what I did.)
Making dreamhack-exclude.lst a bit more relevant

var/skel/dw doesn't exist any more, and we probably shouldn't be
ignoring the .git repository in the backup any more. We also want to
ignore the var/maintain.d directory because it's only ever used for
temporary stuff.
Merge pull request #6 from Sophira/misc-fixes

Misc fixes