Allow the use of synonyms in settings. Refactor settings.

Remove a bunch of obsolete/unused code.

depends/settings/overridesetting.cpp

@@ -0,0 +1,30 @@
+/* Copyright 2013 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "overridesetting.h"
+
+OverrideSetting::OverrideSetting(std::shared_ptr<Setting> other)
+	: Setting(other->configKeys(), QVariant())
+{
+	m_other = other;
+}
+
+QVariant OverrideSetting::defValue() const
+{
+	if (m_other)
+		return m_other->get();
+	else
+		return QVariant();
+}