bump(sys-apps/systemd): sync live ebuild with upstream + local changes

This pulls in the latest changes from Gentoo as of 21 Feb 2014 along
with the CoreOS changes we made in the 207 ebuild.

Hard mask kdbus flag. We don't need to tread into those waters yet.

We will be trying networkd but leave the flag disabled until someone
wants to start working with it.
fix(sys-apps/systemd): Fix a few upstream changes/issues. Add 209.

- Restore openrc use flag, we don't want to pull it in.
- Change cpp #if LIVE to bash if statements to symlinks work.
- Depend on a newer libseccomp, build fails with old versions.
- Depend on lxml if python is enabled.
- Add version 209!
fix(sys-apps/systemd): Patch pkg-config instead of enabling compat libs.

Enabling compat libs is causing ld errors. To keep things like dbus
compiling we can instead just provide the old pkg-config files.

Patch from https://bugs.gentoo.org/show_bug.cgi?id=501860
bump(sys-apps/systemd) bump to 210 release

Fixes first boot and journald issues for me.
fix(sys-apps/systemd): add patch for loginuid issue
fix(sys-apps/systemd): Use stable keywords for systemd 207

Mark our old 207 ebuild as stable and 210 as unstable so we can continue
systemd testing in master.
fix(sys-apps/systemd): Refresh 210 and live ebuilds from Gentoo

This merges changes made upstream. Important changes include:
 - An alternative pkg-config fix, previously fixed in 209 in 7830090d
   but dropped in the bump to 210 in d333420b.
 - Drops networkd use flag, it is always built now.
 - New 210.9999 stable branch live ebuild.
feat(sys-apps/systemd): Start networkd by default
Merge pull request #385 from marineam/systemd2

Systemd 210