Provide numeric key data in state description
Provide numeric key data in state description

Sensor readings have new fields added, allowing some callers
to use easier comparison and lookups.  For example some
may want to have a full setence string for permutation of
reading types, sensor types, and specific event.

Change-Id: I743a32777259516f8febf5a0a62757ce5a4cee59

openstack/pyghmi,benoit-canet/pyghmi,stackforge/pyghmi,openstack/pyghmi