Restore support for older yum: no --downloadonly option, so use
yumdownloader.
Also add some a code to handle some Debian quirks - especially default
rpmdb location in user home...
This better handles dependencies (especially of "Obsolete:" type).
Unfortunately yum install/upgrade checks if running as root. Because we
are only downloading packages, using local "system root" (--installroot
option) no real root access is requires, so use fakeroot to mute yum
error.
Get rid of underscores in filenames, use dashes instead.
This is first part of cleanup in filenames.
"qubes_rpc" still untouched - will be in separate commit.
