* Calculate sampling error rate over a time window

* Create the following variables to control bert testing behavior:
  bert_timeout_ms - Milliseconds to wait for bert sync before timing out
  bert_window_ms - Window of time to calculate sampling error rate percentage
  bert_max_err - Max percentage of error tolerated before going out of sync
  bert_hangup_on_error - Hangup when error occurs (Timeout or going out of sync)

* commit '9215c938':
  FS-6785 - pass and use sample rate in switch_core_session_get_payload_code()

Merge pull request #38 in FS/freeswitch from ~ALEXDG/freeswitch-event-for-gateway-ping:master to master

* commit '388e9638':
  F-5946 add the patches. if in the sofia gateway config the param pin-monitoring is true, then every ping result raise an sofia::gateway-state event

* commit '6753ccf6':
  Missed one of the variable changes!

if read multi times when waiting for a slow client, then bytes is much shorter than datalen
so it could incorrectly terminate the string and data could be lost

* commit '9d9feb64':
  make the tzfile header check look for "TZif" instead of "TZif2"

F-5946 add the patches. if in the sofia gateway config the param pin-monitoring is true, then every ping result raise an sofia::gateway-state event

ref: commit ce96d95c

...rather than `storage`.

ref: commit ce96d95c

FS-5992 #resolve