Client: better arg handling & logging
Client: better arg handling & logging

* Made all parameters name-based for easier outside use
* Now a non-success return code raises an IOError
* Normalized command-line options to use "-" instead of "_" in names.
* Added environment to the list of required parameters
cykl/codespeed,alex/codespeed,nomeata/codespeed,alex/codespeed,cykl/codespeed,nomeata/codespeed