AGJS-187 AeroGear.ajax callbacks should have proper args

[AGJS-187](https://issues.jboss.org/browse/AGJS-187?jql=project%20%3D%20AGJS) is prerequisite for [AGJS-162](https://issues.jboss.org/browse/AGJS-162?jql=project%20%3D%20AGJS) so I have implemented this one as well