Added sim mode test. Fixed self.run_mode. Corrected suite spec.
Corrected config.py to pick up overridden run types.
Tweak scheduler code.
Stop command option to kill active tasks before shutdown.
Stop --kill option for gcylc.
Defined shorter runtime range for tasks.
Minimum time range values.
Merge pull request #502 from hjoliver/501.kill-tasks-on-shutdown

#501 cylc stop --kill: kill tasks on shutdown
Merge pull request #500 from arjclark/simulation-mode-test

fix force run mode