Added new units option in General Form, Tm.  When it's selected, the
source diameter slider in Source Form gets disabled.
If the Ka receiver is choosen, the Data Form's averagePol widget is
hidden, with default of False value used.
In Data Form, when differenceSignal is not selected, the rSigRef and
rAverageRef widgets get disabled.
Removed the smoothing_factor radio group from the Data Form, as a value
other then 1 rarely produces correct results.
After changing Mustang to Mustang 1.5 in DB, altered Source Form so that
the topoFreq widget is disabled for this receiver.
calculator's data form now handles Mustang 1.5 backend: form is hidden,
and dfferenceSignal widget defaults to false.
extended calculator's handling of the source diameter slider.
Calculator's source slider max upped to 26 steps.
Calculator's Data Form's Desired Resoultion max digits uped to 9.
Setting max of src diameter slider to 26.
Fixed bug where Data Form's differencSignal could not be hidden.
Made flux density the default choice for units for SC.
W/ flux density as the default units, src diameter slider should start
at zero.