Add an option to set an Origin whitelist for Websocket and SockJS

This commit introduces a new AllowedOriginInterceptor WebSocket
HandshakeInterceptor. It will filter Origin header value against a list of
allowed origins.

AbstractSockJsService as been modified to:
 - Reject CORS requests with forbidden origins
 - Disable transport types that does not support CORS when an origin check is
   required
 - Use the Origin request header value instead of "*" for
   Access-Control-Allow-Origin response header value
   (mandatory when  Access-Control-Allow-Credentials=true)
 - Return CORS header only if the request contains an Origin header

It is possible to configure easily this behavior thanks to
StompWebSocketEndpointRegistration#setAllowsOrigins(String...).

Please notice that this commit does not change the default behavior:
cross origin requests are enabled by default.

Issues: SPR-12226