Update  Grizzly2WebSocketSupport to support http://java.net/jira/browse/GRIZZLY-1438

The interesting part of this pull request is:

https://github.com/dermarens/atmosphere/commit/ffc2b1fe1d6c8dd080f405cc34b12f431e314b85

which is neccessary after the changes in http://java.net/jira/browse/GRIZZLY-1438