removed app_config from repo

config/app_config.yml

---- 
-default: 
-  socket_host: 0.0.0.0
-  socket_debug: false
-  pod_url: tom.joindiaspora.com
-  mongo_post: 27017
-  socket_collection_name: websocket
-  socket_port: 8080
-  pubsub_server: https://pubsubhubbub.appspot.com/
-  mongo_host: localhost
-  debug: false
-production: 
-development: 
-  pod_url: tom.joindiaspora.com
-test: 
-  pod_url: http://example.org/
-  socket_port: 8081