Many sensors in nodesensors are not useful except when
evaluated as part of nodehealth. Provide an option to allow people
to skip such sensors. Particularly useful in generating time series CSV
data.
Be more sparing with 'ok' and '()' in output. Many of the sensors
have no particular meaning if they are 'ok'.
For a sensor witohut a value, the states are no longer surrounded by
() to reflect that they are more first class rather than describing
a primary value.
nodesensors is not roughly at par with rvitals.
This means more complete handling and recognizing
some of the rvitals shortcuts as well as some mistakes
in the draft. Still lacking are interval/repeat queries.
