First implementation of sr850 interface.
Implemented frequency sweep mode command; Updated documentation.
Implemented start and stop frequency command.
Implemented the Input and Filter Commands; Implemented the Gain and Timeconstant Commands.
Implemented Output and Offset Commands.
Updated documentation.
Added Display and Scale Commands; Added Trace and Scan commands;
Implemented several more SR850 commands.
Implement the last missing sr850 commands.
Merge branch 'feature-sr850' into develop