Add methods getTask and runTask to JPetTaskRunnerInterface
Add methods getTask and runTask to JPetTaskRunnerInterface

Also remove getSubTask method from JPetTaskIO

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