Wrap integration rake in MissingSourceFile rescue to avoid failure when the test gems aren't present.

Switching to settingslogic to manage our configuration. THE FILE FORMAT HAS CHANGED. OLD APP.YML AND APP_CONFIG.YML FILES WILL NOT WORK ANYMORE.
Two important differences:
1. The app only looks in one file for settings: config/application.yml. If you want to override something, do it in that file. It is gitignore'd. If config/application.yml does not exist, or exists but is in the old format, you'll get a nice friendly set of instructions on how to convert your old file.
2. script/server settings are no longer in application.yml. They have their own settings file - copy config/script_server_config.yml.example to config/script_server_config.yml. This is also gitignore'd. script/server will print a message and exit if that file doesn't exist.

rename config/app_config.yml to config/app.yml in accordance to The Redundant Rendundacy Act of 2011

eliminate config/server.sh; use config/app_config.yml.example as base for configuration, config/app_config.yml is now just an overider. This way we can add new configuration options without checking in the application if it's set and the user has to update his app_config.yml only when he want to change something

replaced SOCKET_PORT in config/server.sh with the setting from config/app_config.yml; respect single_process_mode setting in app_config.yml in script/server

Added spec for YOUTUBE_ID_REGEX, we can easily add more youtube url sample here later to avoid polluting application_helper spec