-Events system update order is now choosen according to system priority

-added mixin for adding exluded components using it's type
-demos:
 *added GUI for selecting templates and choosing tools
 *change SpaceInvades SideMove system to not using events for better performance and multithreading
 *added Entites spawning support
 *fixed some Snake demo bugs
 *GUI work's better now

source/ecs/hash_map.d

@@ -211,7 +211,7 @@ struct HashMap(KeyPar, ValuePar, alias hashFunc = defaultHashFunc) {
 		return cast(float) forElementsNum / (elements.length);
 	}
 
-	export void rehash() {
+	export void rehash()() {
 		mixin(doNotInline);
 		// Get all elements
 		Vector!KeyVal allElements;