Fixes and improvements:
- rename arm6 and arm7 releases into armv6 and armv7
- RTSP server: support setupping tracks with arbitrary interleaved IDs (#402)
- HLS: fix CORS issues with HLS player using authorization
- HLS: add Access-Control-Allow-Origin to every HTTP response; add parameter hlsAllowOrigin (#415)
- HLS: skip frames received before the first IDR frame
- HLS: fix crash on armv7 (#440)
- HLS: add Content-Type header (#408)