Placeholder for new command added.
Initial steps of implementation.
Mostly functional implementation of state checker.

 * validate mast method added
 * state lookup for aliased states added
Methods added to check and retrieve states for particular tasks.
Primitive version up and running.
Better wait switch.
Tweaks and tidying.
In correct commands section. Works for remotehosts.
Version for review.
Merge remote branch 'upstream/master' into cylc-suite-status
Merge pull request #288 from arjclark/cylc-suite-status

Cylc suite state CLI utility
Updated the change log.