Add cylc version to the suite environment file.
Made suite daemon cylc version discoverable.
Some style corrections.
Better cylc ping command help.
New command to get suite daemon's cylc version.
Added a new test.
Addressed style review.
Updated Makefile for new cylc-cylc command name.
Merge pull request #1248 from hjoliver/cylc-suite-env.cylc-version

Make a suite daemon's cylc version discoverable.