Improve command parsing

[iparask]

• Always try to strip out the prefix, even if the job name is given.
• If a job has a prefix, always try to strip it and issue an error if it is not there.
• find a way to show where it is not matching? How does python do it with traceback?
• Append an option error when an unknown parameter is passed, warning the use the separate the command from slurmise options with --.