Add possibility to configure admin access to script configuration changes

[bugy]

Based on the following comment:

@bugy this "bug" is actually a feature, I'm leveraging it to separate the admin permissions of admins from different teams which shouldn't manage and access each other scripts. it was completely awesome if this feature was effecting also the script audit screen, which will allow admins to see audits items only of Scripts they are in the "allowed users".
Anyway please don't fix this bug which will actually kill a great feature

Originally posted by @Alonel in #342 (comment)

[bugy]

Now there is "admin_users" setting for a script configuration (also configurable in UI). Only admins, which are listed in "admin_users" would be able to modify a script (and see it on the admin page)