swait record fields

[prjemian]

The synApps swait record does not have all the fields as other records that return a float from the .VAL field. This includes .EGU, .HIHI and a host of other fields in apstools.synApps._common.EpicsRecordFloatFields().

Better to define the apstools.synApps.swait.SwaitRecord() with this start:

class SwaitRecord(EpicsRecordDeviceCommonAll):
    """
    synApps swait record: used as $(P):userCalc$(N)

    .. autosummary::
       
        ~reset

    """
    precision = Cpt(EpicsSignal, ".PREC")
    high_operating_range = Cpt(EpicsSignal, ".HOPR")
    low_operating_range = Cpt(EpicsSignal, ".LOPR")

    calculated_value = Cpt(EpicsSignal, ".VAL")
    calculation = Cpt(EpicsSignal, ".CALC")