Command line handling streamlined.

The usage (ddp-erlang--style means either of three variants):

    sz@sz-nb:~/work/SKA/SKA-RC/MS1/ddp-erlang-style$ ddp-erlang-style --help
    ddp-erlang-style Cloud Haskell implementation

    Usage: ddp-erlang-style COMMAND
      run a distributed dot product program as master or slave on IP:PORT binding

    Available options:
      -h,--help                Show this help text

    Available commands:
      master                   run as master on IP:PORT
      slave                    run as slave on IP:PORT
    sz@sz-nb:~/work/SKA/SKA-RC/MS1/ddp-erlang-style$ ddp-erlang-style master --help
    Invalid option `--help'

    Usage: ddp-erlang-style master [-c|--crash] (-i|--ip IP) (-p|--port PORT)
      run as master on IP:PORT
    sz@sz-nb:~/work/SKA/SKA-RC/MS1/ddp-erlang-style$ ddp-erlang-style slave --help
    Invalid option `--help'

    Usage: ddp-erlang-style slave (-i|--ip IP) (-p|--port PORT)
      run as slave on IP:PORT
Extra arguments at the end of command line.

Command line accepts extra arguments at the end of command line. Program does nothing with them right now, they can be used in future.
Merge branch 'master' of github.com:SKA-ScienceDataProcessor/RC