Adding ExternalCommandListener object.
Merge remote-tracking branch 'upstream/master' into 7224
Merge branch '7224' of github.com:cropalato/puppet-icinga2 into cropalato-7224
Fixed typo
Merge remote-tracking branch 'upstream/master' into 7224
Merge branch '7224' of github.com:cropalato/puppet-icinga2 into cropalato-7224
Merge branch 'cropalato-7224'

Merged in from: https://github.com/Icinga/puppet-icinga2/pull/50