Had this patch sitting around, tested briefly by making an updates.img
for the rawhide boot.iso.

This required a previous commit to do a workaround to prevent pylint
from attempting to spawn a bus while processing imports. This patch
fixes it in a cleaner way by not defining variables at all for them.

For the system bus, add a helper to get a complete connection as an
API.

For the session one, since we only use it in one place, so let's just
internalize it.
---
 pyanaconda/keyboard.py | 10 +++-------
 pyanaconda/safe_dbus.py | 25 ++++++++++++-------------
 2 files changed, 15 insertions(+), 20 deletions(-)