Device type functionality update

Reworked the custom commands to align with the virtual switches set up by badgermanus.  The virtual switches add a lot of value because they allow direct control of any of the 8 relay switches.  One use case would be to set up a motion detector in the yard that can be triggered by a deer which then turns on the specific zone relevant to that detector!  Many other uses as well.

I also added the "poll" and "refresh" capabilities to make the code more in line with the SmartThings ecosystem.

None of the changes appear to affect the SmartApps made by Matt which rely on the "switch" capability and did not directly access the custom commands.

Any comments welcome before I merge with master branch.