add IntTrigMult trigger mode

Using TUCAM_Cap_DoSoftwareTrigger in startAcq().

In the same way, I propose to change the IntTrig mode code to no longer use the Timer but use the SEQUENCE mode.

DhyanaTimer did use the DoSoftwareTrigger, which introduces a overhead of 100ms for each new frame, making not possible to reach the max. frequency (24Hz) on this detector in internal trigger mode.