Improved SCPI Instrument Settings

Current SCPI instrument settings in 3 groups, Common, Locking and Debugging. Since all of these are closely related to VISA, I suggest moving them to a VISA settings group like this:

VISA
  Address
  I/O Timeout
  Locking
    Lock Queries
    Lock Holdoff -> Holdoff
    Lock Instrument
    Lock Retries
  Debug
    Error Checking
    Send VIClear On Conect
    Verbose SCPI Logging