Bypass VRaptor filter in WebSocket requests.

When you try to open a WebSocket connection to a @ServerEndpoint component in your application, the current implementation of the VRaptor filter prevents it from completing.

This fix allows WebSocket requests to bypass the VRaptor filter, hence, succeeding to establish the connection.
Your test are fail. I think that we can change lines from 75 to 76 to test if `chain.doFilter` was called, like this:

```java
vRaptor.doFilter(request, response, chain);
verify(chain).doFilter(request, response);
verify(handler, never()).requestingStaticFile(request);
```

This test ensure `chain` is called and the rest of code wont. Methods like `verify` and `never` are from `org.mockito`.

What you think?