Allow Satellite to sometimes be flaky

[zachsmorgan]

When we have multiple machines (>5) registering simultaneously, sometimes Satellite gets confused and throws an HTTP 50x error which kills the chef-client run.

I think it makes sense to have a second "execute_cmd_maybe?" method (naming is not my forte :)) in the system provider to allow for a command that must be run X times before bailing.

Thoughts?

[thenoid]

sounds good to me