fixed the last of the warning messages in MSVC in mod_exosip.c.  There are now no warning messages at all in all of the freeswitch code.  The dependency libs are still another story.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@63 d0543943-73ff-0310-b7d9-9358b9ac24b2