ARI: Add debug logging for events and responses

This adds DEBUG level logging for ARI websocket events and HTTP
responses similar to what is available for AMI. Logging for ARI HTTP
requests is already adequate for debugging purposes.


git-svn-id: http://svn.asterisk.org/svn/asterisk/branches/12@412565 f38db490-d61c-443f-a65b-d21fe96a405b