better / unified debugging in translate5

Currently debugging and debugging switches are implemented newly on every new big feature.
We need a unified debug management, where dedicated parts of debugging can be en / disabled by configuration.
The parts of debugging would be

• ZfExtended Log → decouple Zend_Mail from Log class hierarchy, since logging has nothing to do with sending mails, but a Logger can use the Mailer as one way of sending log messages
• ZfExtended Log log calls should respect a verbosity level or something
• Enable / Disable Events logging globally
• Enable / Disable Workflow logging globally
• Enable / Disable Worker logging globally
• Enable / Disable Exception Traces by config
  → see therefore the possible runtimeOptions.logging.editor.delete.index.ZfExtended_BadMethodCallException entry
• use different error_log files per configuration (by debug level, or error origin or so)
• Keep the idea of a debugging plugin (per events) in mind
• Introduce different errorlevels (ERROR / WARNING / INFO / NOTICE etc) and add the level to the subject / message.