private WebResponse execAssert(GetMethodWebRequest request) throws Exception {
    return execAndAssert(request,null);
  }
If we're proxying a remote service that tries to set cookies, we need to make sure the cookies are not captured
by the httpclient in the ProxyServlet, otherwise later requests from ALL users will all access the remote proxy
with the same cookie as the first user
src/test/java/org/mitre/dsmiley/httpproxy/ProxyServletTest.java