adjusts users and groups startup scripts to accomdate non-uniqueness

[LBegnaud]

Permission codenames in django are not unique. This iterates through all permissions of a given name to add individually

closes #146

[cimnine]

Thank you for this PR!

Am I understanding this correctly?

• This will not break the current initialisers.
• This changes the behaviour to adding all permissions/groups to a user with the given name. So if there are two permissions with the same name, both are added.

[LBegnaud]

That's correct. The issue is that permission codenames are not unique, so this change does a search for all permission codenames that match the yaml array, then adds each one. I tested with my install and it works. No change to original behavior as far as I know.