Add option to skip scripts

[reaperzn]

It might be useful to add an option to skip some scripts.

We may look into the following options:

--skip-all-scripts
--skip-phase-scripts [ pre-prep | post-prep | pre-apply | post-apply | pre-reboot | post-reboot ]
--skip-script-by-name SCRIPTNAME

The third option would ideally be a glob match although it might be easier to set it as a literal match

[reaperzn]

Complete