Update configure script to check for Zaptel VLDTMF support since this will now be required. If you build and don't have Zap stuff, upgrade your zaptel copy. As well - change some minor things so that we get "checking for" and not "checking checking for".


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@41505 65c4cc65-6c06-0410-ace0-fbb531ad65f3