adding fail_on_single_reject dialplan option that can be set, which then immediately rejects the call even when sent to multiple destinations upon one party rejecting, useful if you are doing a ring all (, separated in the dial string for multiple calls at once) and you want a single rejection to make the call flow to the next action in the dialplan (in combination w/ continue_on_fail) for example to flow to voicemail.  Thanks to George Shaw for this patch.

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@4193 d0543943-73ff-0310-b7d9-9358b9ac24b2