major redesign of the channel spy infrastructure, increasing efficiency and reducing locking conflicts
(nearly) complete rewrite of app_muxmon, renaming the application to MixMonitor and fixing a large number of bugs and inconsistencies
update app_chanspy to use new spy infrastructure


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@6884 65c4cc65-6c06-0410-ace0-fbb531ad65f3