[PVR] Timeshifting: Fixed EpgInfoTag::[IsActive|WasActive|InTheFuture]

Changed EpgInfoTag::[IsActive|WasActive|InTheFuture] to take timeshifting into account. 
Fixes wrong event info shown at several places in kodi UI when timeshifting (e.g. Video OSD).
yes, that one just attracted my attention ;)