eventbus: remove hacks, add sender

examples/eventbus/eventbus.v

@@ -11,6 +11,8 @@ fn main(){
 	some_module.do_work()
 }
 
-fn on_error(p eventbus.Params) {
+fn on_error(sender voidptr, p eventbus.Params) {
+	work := *(*some_module.Work(sender))
+	println(work.hours)
 	println(p.get_string("error"))
 }

examples/eventbus/modules/some_module/some_module.v

@@ -8,14 +8,20 @@ const (
 	eb = eventbus.new()
 )
 
+pub struct Work {
+	pub:
+	hours int
+}
+
 pub fn do_work(){
+	work := Work{20}
 	mut params := eventbus.Params{}
 	for i in 0..20 {
 		println("working...")
 		if i == 15 {
 			params.put_string("error", "CRASH!!")
-			eb.publish("error", params)
-			eb.publish("error", params)
+			eb.publish("error", work, params)
+			eb.publish("error", work, params)
 			return
 		}
 	}