LiveStreaming: PROGRAM_ID has been deprecated
Fix memory leak in HLSSegmenter; Tweak LiveStreaming output

* HLSSegmenter: Remove expired segments from segment_idx, fixing a memory leak
* HLSSegmenter: Tweak rules for creating a new segment to fix what seemed to be
  a logic issue on tied timestamps
* Use relative paths in LivStreaming stream indices to cut down on file size