Default AIP permissions configuration

It is possible to change how AIP permissions are granted to users and groups when creating an AIP on the Web interface or when creating it via ingest. To do so, the following configurations must be changed in the roda-core.properties file.

If we wish to add a group as a super group that has full permissions when creating aip’s, we simply need add the following lines:

 # Admin users or groups so AIPs can be administered
    
 core.aip.default_permissions.admin.group[] = administrators
    
 core.aip.default_permissions.admin.group[].administrators.permission[] = READ
 core.aip.default_permissions.admin.group[].administrators.permission[] = UPDATE
 core.aip.default_permissions.admin.group[].administrators.permission[] = CREATE
 core.aip.default_permissions.admin.group[].administrators.permission[] = GRANT
 core.aip.default_permissions.admin.group[].administrators.permission[] = DELETE

The lines above configure the administrators group. If we wanted to add a super user, for example, an admin user, we would do it like so:

 core.aip.default_permissions.admin.user[] = admin
   
 core.aip.default_permissions.admin.user[].admin.permission[] = READ
 core.aip.default_permissions.admin.user[].admin.permission[] = UPDATE
 core.aip.default_permissions.admin.user[].admin.permission[] = CREATE
 core.aip.default_permissions.admin.user[].admin.permission[] = GRANT
 core.aip.default_permissions.admin.user[].admin.permission[] = DELETE

Finally, we can also add other groups, other than super groups. These are normal groups, and do not have full permissions.

 # Additional group permissions
 core.aip.default_permissions.group[] = archivists
 core.aip.default_permissions.group[] = producers
 core.aip.default_permissions.group[] = guests
    
 core.aip.default_permissions.group[].archivists.permission[] = READ
 core.aip.default_permissions.group[].archivists.permission[] = UPDATE
 core.aip.default_permissions.group[].archivists.permission[] = CREATE
    
 core.aip.default_permissions.group[].producers.permission[] = READ
    
 core.aip.default_permissions.group[].guests.permission[] = READ

A requirement might be that the user that created the AIP must belong to one of the groups defined on the configurations file and it has READ and UPDATE permissions at least. If the intersection is empty, or generally, if the set permission ends up not providing the user with at least READ and UPDATE permissions to the created AIP, then these permissions are loaded as the minimum permissions from the config file.
```
 # Intersect creator groups with the configuration groups
 core.aip.default_permissions.intersect_groups = true

 # System expects a minimum set of direct or indirect permissions for the creator (DO NOT CHANGE THIS!)
 core.aip.default_permissions.creator.minimum.permissions[] = UPDATE
 core.aip.default_permissions.creator.minimum.permissions[] = READ
```

By default, and to conform to legacy behaviour, the creator user is granted all permissions when creating an AIP.