added few SigCh setter methods
added few SigCh setter methods

wkrzemien/j-pet-framework,JPETTomography/j-pet-framework,alexkernphysiker/j-pet-framework,alexkernphysiker/j-pet-framework,alexkernphysiker/j-pet-framework,wkrzemien/j-pet-framework,wkrzemien/j-pet-framework,JPETTomography/j-pet-framework,wkrzemien/j-pet-framework,alexkernphysiker/j-pet-framework,JPETTomography/j-pet-framework,wkrzemien/j-pet-framework,alexkernphysiker/j-pet-framework