Instead, caclulating average bandwidth by dividing the sum of the
sizes of every segment by the sum of the durations of every segment.
This aligns with the requirement in HLS spec:
https://tools.ietf.org/html/draft-pantos-http-live-streaming-23 4.1.
BandwidthEstimator is also simplified to handle all blocks only.
Fixes#361
Change-Id: I89e7d415a841f4d4048f199de8dae7ffa250467b
Allow the output file to contain template identifiers like $Number$,
$Time$ etc. Unlike the actual template used in SegmentTemplate, the
identifiers in output will be populated before pushing to the DASH
manifest.
Issue: #384
Change-Id: Ife1caadb6fccd32167fa1bc83fe2afcb2d2ad087
KongQun Yang