Add a 'lower' filter to the templates to replace string.lower which no
longer exists. Fix udev_escape, the strings are already unicode, and
drop --chdir from runcmd. It wasn't ever used, and passing cwd to the
new runcmd isn't supported.
live media isn't exactly the same as the Anaconda install media. Right
now this amounts to needing a root= cmdline argument but in the future
there may be other differences.
This also reverts 5437557846 on the new copies of the templates.