The following rules must apply for a user to be able to delete a content object in ContentService methods

deleteContentObject

1. User has ROLE_ADMIN or is SYSTEM user (It is supposed that user SYSTEM has all roles)
2. User is the owner of the object
3. User is not the owner of the object but content object has accessibility.canBeDeletedBy
     whose value is ALL, or contains at least one of the roles user possesses, or explicitly contains user's id
4. Content type is personObject (that is its qualified name is {http://www.betaconceptframework.org/schema/betacms/identity/person}personObject), identityStore repository is the same with the repository and user has role CmsRole.ROLE_CMS_IDENTITY_STORE_EDITOR and property 'personAuthentication.username' is the same with user identity.