Updated: [rhinstaller/anaconda/pulls/190 rhel7-branch] rhel7 backports

[dashea]

This is the commits from #181 and #182, backported for rhel7. The differences are minor but _just barely_ enough to make me want another quick review.

The differences from the above commits are:

- 231ac70: also reverts a66cb15
- 99c97dd: dnfpayload vs. yumpayload; the fix is the same, it's just in a different file.
- d844db8: resolve some parse-kickstart conflicts - `commands.network.RHEL7_Network` vs. `commands.network.F22_Network`, etc.
- faf2432: resolve conflict in dracut/module-setup.sh: RHEL7 doesn't have `PYTHONHASHSEED=42`
- 679448a: RHEL7 handles chronyd and ntpd; rather than checking to see if the files exist, just try to modify them - the worst that can happen (AFAICT) is a warning in the log. NBD.