[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).
eeh void params are correct, both in C and in C++. they may not be needed, but there's no need to change these, and in this case, it actually looks like a valid warning, because GetCurrentTime is some macro that is being expanded on windows.