add reboot alias and completions
try to always kill control masters on shutdown
refactor rename

filter_dangerous_actions -> remove_harmless_actions
The previous name implied the contrary.
improve test results, prompt confirmation @reboot
sort imports
sort imports
implement decorator to log errors

This is convenient to use in command definitions since we have no error
reporting when an error happens while creating plans.
use log_exceptions to guard reboot()
rework logger silencing for tests

Since injecting the logger in a decorator is done at import time,
patching the logger local no longer works (the setUp would run after
import time and thus still patch the logger local but not affect the
decorated function's logger in any way).
pep8 whitespace
fix test typo which led to another typo :rat:
log exceptions that occur during compare_versions
log exceptions that occur during restart
pep8 whitespace
rename module validate -> service_validation
Improve error message

* Add hint to very common reason of problem
* Improve notation
Merge pull request #19 from mwoitschitzky/master

Improve error message
remove broadcaster connect calls

The default is now always connected.