hidden-773347: Allow hidden parameters
hidden-773347: Allow hidden parameters

Bonus DVD extra.
paramSpec is what the user passes to 'addCommand' in the param section.
By reflecting the 'hidden' attribute in the Parameter class then we get
the (nearly) free bonus feature of hidden parameters.

joewalker/gcli,mozilla/gcli,mozilla/gcli,joewalker/gcli,mozilla/gcli