Generally tried to make them more reliable and execute quicker.
They all now load the listen script as a trick to make sure input
sources are fully read, but also terminate() at appropriate times
so that they don't take more time than needed. They're also all
serialized with the 'comm' group so listening on a port doesn't
interfere with the communication tests.
* change internal reader interface again
* remove some quite embarassing bugs that must have been in the interface for rather long
* add different read methods to script & internal interface (like normal, streaming, etc). Not implemented in ascii reader yet.
