switch doxygen generation in sofia-sip around to use configure generated files.  This should avoid some problems with warnings and errors when builing the manpages.  You will probably need to autoreconf and configure sofia-sip for this

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@4979 d0543943-73ff-0310-b7d9-9358b9ac24b2