added run script to build pak files

Run.hx

@@ -0,0 +1,17 @@
+class Run {
+
+	public static function main() {	
+		var args = Sys.args();
+		var currentDir = args.pop(); // current directory
+		switch( args[0] ) {
+		case null:
+		case "pak":
+			var res = args[1];
+			if( res == null ) res = "res";
+			hxd.fmt.pak.Build.make(currentDir + res, currentDir + "res");
+		case cmd:
+			Sys.println("Don't know how to run '"+cmd+"'");
+		}
+	}
+
+}