Reverted previous commit and added call stats functions to linphone API
Fix compilation with cmake.
Add missing is_composing_received callback when a text message is received.
Fix compilation (missing const keywords).
Fixed tutorials for android
fix problem with media encryption not set in params for incoming calls
* fix incorrect behavior when the body of an INVITE cannot be understood or parsed.
Previously it was answering 200Ok.
* do not send 415 but 488 in case of incompatible codecs, which is more correct according to the RFC.
415 should be replied if the body cannot be understood (for example: is not application/sdp)