Support passing parameters to the underlying command (action)

[ghost]

On the command line:

Example: sequencer poweroff node[104-109] -- --noexec --Debug foo bar.

The underlying poweroff action will receive options --noexec, --Debug and parameters foo and bar.

Note however that since a given ruleset might execute several actions, some variables may be passed to some actions, other might not. Therefore, there should be a way to specify which variables should be passed to which action.

Something like: rule_name:'--option1 --option2 opt2_param2 param1 param2' might be a first trivial solution.