WebServiceWorkItemHandler HTTP BasicAuth support.

The jBPM WebServiceWorkItemHandler should support HTTP Basic Authentication.

Because the WIH is backed by the CXF Dynamic Client, we should be able to implement something like this:

HTTPConduit http = (HTTPConduit) client.getConduit();

AuthorizationPolicy authPolicy = new AuthorizationPolicy();
authPolicy.setAuthorizationType("BASIC");
authPolicy.setUserName("ddoyle");
authPolicy.setPassword("jboss@01");

http.setAuthorization(authPolicy);

We do need to find a proper way to expose this to users though.