Liblinphone:

Start count of potential configuration to 1

Compatibility with Avaya and FreeSwitch servers:
- call is paused when receiving a response with all streams having RTP port set to 0
- add support for 100rel support/require level

belle-sip:
Test scenario where connection and origin IP are not identical

liblinphone!1446 (merged) belle-sip!207 (merged)