Modified Sensors and Equipment Extensions

I created a new feature branch from the master and re-implemented
Amber’s Sensors extension plus all of the changes we made this morning
based on our meeting.  This should make it easier to merge back into
the Master branch.
Added Equipment Annotations
Minor changes to what was open in the editor.
Minor modifications to diagrams. No changes to schema
Modifications to sensor and equipment extensions

Based on the call today, I made a few modifications to these
extensions.  I’m committing now and will merge with Master.
Merge pull request #54 from UCHIC/Sensors_Extension_Final

Merging new work on Sensors and Equipment schemas into the Master branch.