- With refactored code, introducing new kinds of actions
is very few lines of code. Allow disabling targets
(services was already possible). Allow masking units,
but as a special case require the complete name.
FIXES#975
- The three steps of modifying services in the target
system do basically the same thing, so factor out
the loops and logging into a systemctl() function.
- Log to warning() instead of just debugging, on failure.
