Ditch keyboard mover, shooter, interval shooter. All of that is game code not engine. Added key handler and scheduler. Can also now duplicate components on an element (key readers for example)

element.go

@@ -61,7 +61,7 @@ func (elem *Element) collision(other *Element) error {
 	return nil
 }
 
-func (elem *Element) AddComponent(new component) {
+func (elem *Element) AddComponentUnique(new component) {
 	for _, existing := range elem.components {
 		if reflect.TypeOf(new) == reflect.TypeOf(existing) {
 			panic(fmt.Sprintf(
@@ -69,6 +69,10 @@ func (elem *Element) AddComponent(new component) {
 				reflect.TypeOf(new)))
 		}
 	}
+	elem.AddComponent(new)
+}
+
+func (elem *Element) AddComponent(new component) {
 	elem.components = append(elem.components, new)
 }