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
16 files changed