Packets: Document DataPacket, safe_data_iterator and exceptions
Packets: Move bundle documentation out of the Packets documentation
Scheduler: Make test more robust (add sleep ...)
Move all local dictionary words into senf.dict

* Place all modules in the senf::ppi::module namespace
* Place all connectors in the senf::ppi::connector namespace
* Name input modles 'Reader', output modules 'Writer'
Added specification for SocketReader / SocketWriter and PassiveQueue
Removed three-argument connect() form

Layout update