added usage help for authentication options
initial code for SpaceMon client-side utility (work in progress)
Use script's own name in printout; add --version option.
experimental  changes: make auth options work (no require_order), however this  breaks passing  options from the NS command,  which rely  on require_order...
Refactoring code for SpaceMon phase 2: this is replacing both PHEDEX::Namespace::SpaceCountCommon and DMWMMON::StorageAccounting::Core