We need to generate resource files for the exceptions.
Probably the best way to do this is to map the
ID to the message:

GMBAL101 = "Required type is {0}"

This requires some changes:

1. Every message must have an ID.  currently only log messages have IDs
   This means moving the ID field from @Log to @Message.
2. The basic processing should stay the same:
    - Return type of String: cannot return an exception or generate one, but
      will return a formatted I18N message.
    - Return type of an Exception: will generate exception
    - Return type of void: may log (if @Log present), otherwise useless.
    - A log is generated only if @Log
3. We can build a simple scanner that takes as arguments the names of the classes
   to scan for annotated methods.
