Fix issue with systemd template units which does not return properties;
this means running `systemctl show user@` returns an error instead of a property map
Update changes and version
Add missing makefiles
Make tests pass
Check for exit status, not stderr
Merge pull request #202 from vmoravec/fix-empty-properties

Fix issue with systemd template units

Our code relied on non-existent services returning a (bogus?) set of properties where `LoadState=not-found`. But `@` is a special case: if the instance identifier is missing, we get an early syntax error:
> \# systemctl show getty@.service
> Failed to get properties: Unit name getty@.service is not valid.
Do not change service names as they can be frozen (bnc#870803)
UPdate changes and version
Merge pull request #205 from vmoravec/fix-frozen-service-name

Do not change service names as we do not own them (bnc#870803)
Add more systemd unit commands and adapt Service
Update changes and version
Merge pull request #206 from vmoravec/add-more-systemctl-methods

Add missing systemd unit commands and adapt Service
Fix enabling services in inst-sys
Use local variable `command`
Merge pull request #207 from vmoravec/systemd-inst-sys-bug

Fix enabling services in inst-sys | bnc#870949
Fix failing tests
Merge pull request #208 from vmoravec/systemd-inst-sys-bug

Fix failing tests
add help about tree navigation (bnc #840672)
add new control option to enable sshd(bcn#865056)
Merge pull request #209 from gabi2/master

add help about tree navigation (bnc #840672)