anchor.diff:  
   [source,java,title="Backend.java"]
   ----
  -	[..]
  -	
  +    [..]
  +
   	public <T> T doExecute(Transaction<T> transaction) {
  -		if (!Authorization.isActive() || Authorization.getInstance().isAllowed(transaction)) {
  +		if (Authorization.isAllowed(transaction)) {
   			try {
   				currentTransaction.set(transaction);
   				return transaction.execute();
  
positive.code: ----
  Note that packages don't inherit there roles from their parent package. This would lead to a error-prone complexity.
  
  == Authorization configuration
  The Authorization class defines the available users and their roles. There are several specializations to this class:
  
  - The TextFileAuthorization takes a file as input for the users and their passwords. The format of this file is described below.
  - The PersistenceAuthorization uses a Persistence instance for that. The Persistence instance can be the one used for all other business entites or a special one.
  - The JaasAuthorization connects Minimal-J to the authorization provided by Java itself.
  
  Which one of this specializations is activated is defined via application properties or the application can set the
  current Authorization. This method has also the highest priority:
  
   1. The application sets the Authorization object with the static method setInstance at startup. Note that the Authorization
   object cannot be replaced once it is set. 
  
   2. The property MjUserFile is set to a file.
   
   3. The property MjJaasConfiguration is set.
   
   4. If nothing from above the Authorization is disabled. The user will not see the login buttons.
  
  === The user file format
  The file defining the users has a special format. The format is very similar to the one used by Shiro.
  
  
negative.code: 	}
  ----
  
  This seems readable not only for the compiler. The Authorization class asks the Subjet class who is logged in (in respect of
  the current Thread). It also provides the method to check if a Transaction is allowed.
  
  NOTE: There are two quite similar classes called Subject and User. Subject has more to do with who is
  