trancode: fix time_base and pkt_sri for audio, other cosmetic updates
global headers: create own AAC/MP4A header only if a valid does not exist
libav muxer: add AVMATROSKA muxer type
Makefile.ffmpeg: enable h264_mp4toannexb bsf for libav muxer
Makefile.ffmpeg: prefer static linking for x264, vpx, vorbis libs to avoid conflicts with distro
AAC fixes (ADTS header) in transcoder and libav muxer
Revert "Makefile.ffmpeg: prefer static linking for x264, vpx, vorbis libs to avoid conflicts with distro"

This reverts commit 8e876995f352b28dc7ca0f5ad683d82e35b38370.

It does not work..
WEBUI: help changes, cosmetics and icon
libav muxer: added WEBM support
descrambler: fix TSS_NO_ACCESS reset for buffered packets
remove pkt_merge_header()

- rename pkt_header to pkt_meta
- unify logic for the metadata processing
- add meta field to components to the htsp stream start message
htsp: log subsystem should be lowercase
transcoding: simplify streaming_start_t structure copy
DVR: the dvr entries should be accessed with ACCESS_RECORDER proviledges
htsp: filter out the profiles and dvr configs without granted access
transcode: fix H264 decoding
DVR: log dvr entry delete operation
transcode: remove h264 side data creation, it's not required
transcode: free extradata from context structures
muxer_libav: fix memory leaks