Disable plymouth to workaround not reaching sysinit.target

Resolves: rhbz#1060789
Set multilib_policy=best in the yum config.

Resolves: rhbz#1062714
Merge systemd workaround into old-extrabuilds
Merge multilib into old-extrabuilds
New unofficial version 0.7.8.2
Handle missing version arguments

Workaround the different handling of missing arguments between argparse
and optparse.

Resolves: rhbz#1069836
Merge the new optparse fix to always return a string
New unofficial version 0.7.8.3
Add an option --cleanup-post to cleanup packages in post scripts.

Resolves: rhbz#1070603
Merge in --cleanup-post option
New unofficial build 0.7.8.4