Multiple fixes for OpenBSD rcctl handling.

* Use the newly added 'default' argument to know if the default flags are set
  or not.
* Handle that 'status' may either return flags or YES/NO.
* Centralize flag handling logic.
* Set action variable after check if we need to keep going.

Big thanks to @ajacoutot for implementing the rcctl 'default' argument.
Merge pull request #2 from eest/openbsd_rcctl

Multiple fixes for OpenBSD rcctl handling.