Basic support for X-RTP-Stat reports in BYE/200 OK
Fix return condition to avoid injecting stats when there are none
call: cancel local timer on call_progress()

for incoming calls, we start a local timer of 120 seconds.
this timer is stopped when the call is answered with
200 or 183.

issue was reported by Victor Sergienko, thanks!
move struct stream to core.h
Merge remote-tracking branch 'upstream/master'
Move XRTP stats to audio and implement EN/DE parameters
Minor cleanup
Fixed JI value to timestamp-units based on codec audiorate
Cleanup of XRTP stats print function
rtpstat: fixup some formatting
Merge branch 'lmangani-master'
fix warning
remove support for Symbian OS

R.I.P. Symbian it was nice to know you, too bad the
people at Nokia did not take better care of you ..
dtls_srtp: use DTLS-api from libre v0.4.9

for the dtls_srtp module to compile, you now need libre v0.4.9
or later.

also added note about dependency to libre v0.4.9
in README and Debian file
srtp: split srtp-module into 'srtp' and 'libsrtp'

libre v0.4.9 has a very fast and robust SRTP-stack and we want
to use it in baresip. however libsrtp is also working so we want
to keep the module using libsrtp around for a while.

two modules providing SDES-SRTP:

- libsrtp.so  -- SRTP using libsrtp
- srtp.so     -- Native SRTP-stack in libre
dtls_srtp: use SRTP-stack from libre
modules: use warning() instead of DEBUG_WARNING()
syslog: use output of logging framework
updated some module documentation
dtls_srtp: fix a warning