Merge pull request #769 in FS/freeswitch from feature/FS-8836-support-ffmpeg-2.8-and-3.0-in-mod_av to master

* commit '1641fccd':
  FS-8836 fix deprecated warning on newer ffmpeg

* commit 'bdeacb1d':
  FS-8751 [Conference Play Video Total Time and Current Time]
  FS-8748 FS-8751 check current play_status
  FS-8748 track pdf total pages and current page
  FS-8754 add ability to read high quality PDF
  FS-8750 implement file_seek for video files

Merge pull request #677 in FS/freeswitch from ~JAONZE/freeswitch:bugfix/FS-8765-a-settings-menu-which-discards-expensive to master

* commit 'd3b4b492':
  Settings modal rework -> panel slider at top

Merge pull request #766 in FS/freeswitch from ~O_EMILIANO/freeswitch:bugfix/FS-8959-memory-leak to master

* commit 'f683c78a':
  FS-8959: [mod_av] fixed memory leak problem in encoding h264

FS-8959: [mod_av] fixed memory leak problem in encoding h264, fixed

FS-8959: [mod_av] fixed memory leak problem in encoding h264

FS-8970 - [verto_communicator] Setting 'none' for useSpeak/useMic/useCamera when calling a secondary canvas

Merge pull request #762 in FS/freeswitch from ~PIOTRGREGOR/freeswitch:bugfix/FS-8961-avmd-increase-robustness-of-variance to master

* commit '63a30499':
  FS-8961 Increase robustness of estimation

Merge pull request #761 in FS/freeswitch from ~PIOTRGREGOR/freeswitch:bugfix/FS-8960-avmd-set-buffer-position-to-beginning to master

* commit 'fce7cfee':
  FS-8960 Set buffer position to beginning on reset

Merge pull request #763 in FS/freeswitch from ~DCOLOMBO/freeswitch:bugfix/FS-8963-fix-label-status-call to master

* commit '7525bffc':
  FS-8963 - [verto_communicator]  fix label status call

Again, this shouldn't fix anything, but should make debugging easier.

FS-8312

Add optional requirement of consecutive streak
of estimations in SMA buffer. Fix definitions.
Add options to control debugging/printing.

* Remove unnecessary memset
* Narrow the scope of the global lock on session initialization
* Assert for couple of expected pointers

This won't fix anything, it's just maintenance clean up done
while investigating FS-8312.

Now buffer position is reset to 0.