add EventsBus class to use com.squareup.otto.Bus as an singleton to oversee all events;
add GetRequestResultEvent class;
add constructor for GetRequest class to have the caller id to be required;
add otto:1.3.5 as dependency for its Bus feature;
update proguard-project.txt to ensures otto's annotated methods won't be removed;
update GetRequest class to make it post a GetRequestResultEvent to EventsBus once its background works are done;
register the activity on create and unregister it on destroy;
add method to subscribe the otto changes on GetRequestResultEvent;