Merge branch 'master' into dev_multicall

diff --cc coreapi/linphonecore.c
index 5b4779680d2bb599af9506db83d79549586bc190,1bed57f2cc6022ce8ae60cf4d3bf9631ff75710f..5f7ae7afa7a5a61c8b800e9088226416f81073e1
--- 1/coreapi/linphonecore.c
--- 2/coreapi/linphonecore.c
+++ b/coreapi/linphonecore.c
@@@ -1857,9 -1999,10 +1857,10 @@@ LinphoneCall * linphone_core_invite_add
                err=linphone_core_start_invite(lc,call,dest_proxy);
        }else{
                /*defer the start of the call after the OPTIONS ping*/
 -              call->state=LCStatePreEstablishing;
 +              call->state=LinphoneCallPreEstablishing;
                call->ping_op=sal_op_new(lc->sal);
                sal_ping(call->ping_op,from,real_url);
+               sal_op_set_user_pointer(call->ping_op,call);
                call->start_time=time(NULL);
        }