+ Gulmay `MP1` xray controller (as used at OPMD)
+ Added functionality to support `parser` function accepting as arguments
`value` and `setting` in `SETTINGS` dictionary of a device to specify
parsing behaviour for `query()` call.
- Changes to `SCPIInstrument` and `VISAInstrument` to support SCPI-like but
not SCPI-compliant protocols such as that used by MP1.
- Added direct overrides for termination characters, bits per byte,
termination bits, etc. for serial VISAInstruments.
- Changed `set()` in SCPIInstrument to support devices that immediately
respond to commands with identical read-back.