Improved error handling.

Added a sensible exception in case no services are being discovered at
the chosen endpoint.
WADL parser now warns if some parameters are missing.
Updated license notes.
Finished service specific help string.
First version of waveform retrieval.
Waveform downloading works.
Added event service.
Added "format" to the list of not-used parameters.
Variable debug flag.
Added station downloading to client.