API differences in spandsp 0.0.6pre1 and higher

(closes issue #13688)
 Reported by: irroot
 Patches: 
       app_fax-span6.patch uploaded by irroot (license 52) with minor modifications by me


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@148868 65c4cc65-6c06-0410-ace0-fbb531ad65f3