added no fork mode to the executable so it can be used w/ sipx watchdog service.  This mode is not available on windows as we do not fork on windows regardless.  Thanks to Paweł Pierścionek for the contribution.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@3999 d0543943-73ff-0310-b7d9-9358b9ac24b2