Add custom commands options, rebase of PR #44

[geek-merlin]

Add options to custom commands. Rebase of #44.

[claudiu-cristea]

I think we can add, along options, all that is missed for a command: description, aliases, usage. Or it would be too much for this PR?

[claudiu-cristea]

Also, could you, please change the base branch to #44? Then I’ll merge it there so that we see the tests running (PRs from forks are not tested)

[geek-merlin]

Oh that's great @claudiu-cristea that you chime in to this effort.

Yes, i'm willing to not only scratch my itch, but scratch thoroughly.

Also, could you, please change the base branch to #44?

I don't see anything like that as base branch choice, and don't think it works this way, or i understand it wrongly. Afaik github is not so friendly about different non-owners committing to a PR. Any idea? (EDIT: Maybe you add me to your fork or i add you to mine.)

[geek-merlin]

As of features: Having thought about it, do we really want and need reverse inheritance of options? We can always pass any option value explicitly, and explicit is often better than implicit. Also code will be much simpler, so also need fewer tests.

[geek-merlin]

Worksforme in some simple manual tests. Command description etc. is in.

I had to add SelfProcessingRoboConfig to make it possible to use option provided config in variables. Doing it with less magic would break BC, sigh.

[geek-merlin]

Made some fixes and improvements, now using it happily in a complex deployment script.

[geek-merlin]

Looks like the SelfUpdatingRoboConfig in this PR fixes or is related to #135.