Add contributed EAGI proxy, which provides FastAGI functionality for EAGI, while also

buffering the audio stream.
Reported by: devil_slayer
Patch by: devil_slayer
Closes issue #8921


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@89077 65c4cc65-6c06-0410-ace0-fbb531ad65f3