got rid of dependency injection, it doesn't add anything at this point and only slows down things and makes a mess. Also some refactoring.

src/yugecin/opsudance/core/NotNull.java

@@ -0,0 +1,23 @@
+/*
+ * opsu!dance - fork of opsu! with cursordance auto
+ * Copyright (C) 2017 yugecin
+ *
+ * opsu!dance is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * opsu!dance is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with opsu!dance.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package yugecin.opsudance.core;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+@Retention(RetentionPolicy.SOURCE) public @interface NotNull {}