fixed mesa support

libs/mesa/haxe/System.hx

@@ -4,6 +4,7 @@ class System {
 
 	public static var width = 800;
 	public static var height = 600;
+	public static var vsync = true;
 
 	public static var buffer : haxe.io.Bytes = null;
 	public static var ctx : mesa.Context;
@@ -32,6 +33,10 @@ class System {
 			throw "Failed to init GL API";
 		return true;
 	}
+	
+	public static function emitEvents(_) {
+		return true;
+	}
 
 	public static function present() {
 	}