Adding SIS3302 RoIs as Counter in the MeasurementGroup

As described in section 11.2.10 the counts in RoIs defined in the SIS3302 Tango device can be used as counters in Sardana. These counters can be introduced in the measurement group like any other counter. The measurement group has to contain not only the counters corresponding to the RoIs but also the oned experimental channel corresponding the the SIS3302 device the RoIs belongs to. The device of the class SIS3302Master can be also used to introduce the sum of all SIS3302 channels as counter in Sardana, this is described in section 11.2.14.