Add support for writing Unix epoch-relative tracks to HLS, add proper cleanup of all Targets obtained by an Output

src/ogg/ogg-demuxer.ts

@@ -448,7 +448,7 @@ class OggAudioTrackBacking implements InputAudioTrackBacking {
 		return this.bitstream.sampleRate;
 	}
 
-	getTimestampsAreRelativeToUnixEpoch() {
+	isRelativeToUnixEpoch() {
 		return false;
 	}