fix context path for the popup example

[GoogleCodeExporter]

similar to issue 4

1. LoginViaPopupServlet, change line 108
    realm.append(req.getContextPath())
        .append(REDIRECT_PATH);
    session.setAttribute(RETURN_TO, realm.toString());

2. at popup.jsp, change the javascript from line 94 to:
              url: "<%=request.getContextPath()%>/hello?size=short",
              cache: false,
              success: function(response) {
                $("#welcomePane").html(response);
              }
          });
        } else {
          window.location = "<%=request.getContextPath()%>/hello";
        }
      };

I'm able to get the example working without problem

Original issue reported on code.google.com by mingfai...@gmail.com on 23 Feb 2009 at 1:26