Add dependency on Ratchet and react ZMQ
Add check on libevent for production
Remove signal listener once a signal has been caught
Add task manager broadcaster subscriber
Minimal fix for callback declaration
Add Websocket server
Add WebsocketServer command
Add patch to version 3.9.0-alpha.11
Bump to version 3.9.0-alpha.11
Add useful infos in session storage
Add authorization strategy for WAMP topics
Address PR comments
Merge pull request #944 from romainneutron/websockets

[3.9] Add websocket server