- attempt to reconnect redis pubsub subscriber if disconnected

   see https://ria101.wordpress.com/2011/12/12/concurrenthashmap-avoid-a-common-misuse/
 - Noticed that Red5 became slow to response after a while and usin Yourkit saw that
   a lot of threads are blocked in GlobalAudio.getGlobalAudioStream

 - update red5 to bring in fix for connections not cleanedup properly which may be cause OOM Exception

looks like it's working fine now, still need more testing with a large number of users; also GLOBAL_AUDIO_7* shouldn't appear in the users window

still working on improving the global audio code quality, trying to make it work properly, not there yet; we're probably going to create a new CallAgent for the user who listens to the global audio, because the implementation is still not straightforward

more cleanup and refactoring; global audio is still buggy - at some point it duplicates a global audio consumer internally, and when the consumer disconnects, bbb-voice sends him two disconnects, which breaks the logic inside the phone module; also, when it happens, the global audio stream is never closed anymore

STEPS
cd ~/dev/tools
wget http://services.gradle.org/distributions/gradle-1.7-bin.zip
unzip gradle-1.7-bin.zip
ln -s gradle-1.7 gradle
vi ~/.profile

export GRADLE_HOME=$HOME/dev/tools/gradle
export PATH=$PATH:$GRADLE_HOME/bin

source ~/.profile

changed joingGlobal to listenOnlyMode
Removed old debug messages