Prevent unexpected session creation

[yanchevsky]

Every time a session is accessed, a session is created automatically. This is incorrect behavior if data placement into session is not used.
Problematic place:

public class SessionFacade implements Map {
...
    public Object get(String name) {
        return RequestContext.getHttpRequest().getSession(true).getAttribute(name);
    }

...
}

[ipolevoy]

@yanchevsky you can push the code here, now that branches settled