Implement ticket #982: Support for SIP Message Summary/Message Waiting Indication (MWI, RFC 3842)
 - PJSIP-SIMPLE:
    - implement MWI
 - PJSUA-LIB:
    - added "mwi_enabled" flag in account config
    - added "on_mwi_info" callback
 - pjsua app:
    - added "--mwi" option to enable MWI on account
    - added simple callback to log the NOTIFY message
 - other:
     - added SIPp scenario files to simulate UAS side
 - build:
     - added MWI support on VS6, VS2005, MMP, and Makefile


git-svn-id: https://svn.pjsip.org/repos/pjproject/trunk@2968 74dad513-b988-da41-8d7b-12977e46ad98
diff --git a/pjsip/src/pjsua-lib/pjsua_core.c b/pjsip/src/pjsua-lib/pjsua_core.c
index 0e39076..6e41cbe 100644
--- a/pjsip/src/pjsua-lib/pjsua_core.c
+++ b/pjsip/src/pjsua-lib/pjsua_core.c
@@ -820,6 +820,9 @@
     status = pjsip_pres_init_module( pjsua_var.endpt, pjsip_evsub_instance());
     PJ_ASSERT_RETURN(status == PJ_SUCCESS, status);
 
+    /* Initialize MWI support */
+    status = pjsip_mwi_init_module(pjsua_var.endpt, pjsip_evsub_instance());
+
     /* Init PUBLISH module */
     pjsip_publishc_init_module(pjsua_var.endpt);