Move all the things (YES. Move them.)

Also, implemented some basic modlist logic, to be wired up.

logic/InstanceFactory.h

@@ -0,0 +1,80 @@
+/* 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.
+ */
+
+#pragma once
+
+#include <QObject>
+#include <QMap>
+#include <QList>
+
+#include "InstanceVersion.h"
+
+class InstVersion;
+class BaseInstance;
+
+/*!
+ * The \bInstanceFactory\b is a singleton that manages loading and creating instances.
+ */
+class InstanceFactory : public QObject
+{
+	Q_OBJECT
+public:
+	/*!
+	 * \brief Gets a reference to the instance loader.
+	 */
+	static InstanceFactory &get() { return loader; }
+	
+	enum InstLoadError
+	{
+		NoLoadError = 0,
+		UnknownLoadError,
+		NotAnInstance
+	};
+	
+	enum InstCreateError
+	{
+		NoCreateError = 0,
+		NoSuchVersion,
+		UnknownCreateError,
+		InstExists,
+		CantCreateDir
+	};
+	
+	/*!
+	 * \brief Creates a stub instance
+	 *
+	 * \param inst Pointer to store the created instance in.
+	 * \param instDir The instance's directory.
+	 * \return An InstCreateError error code.
+	 * - InstExists if the given instance directory is already an instance.
+	 * - CantCreateDir if the given instance directory cannot be created.
+	 */
+	InstCreateError createInstance(BaseInstance *&inst, InstVersionPtr version, const QString &instDir);
+	
+	/*!
+	 * \brief Loads an instance from the given directory.
+	 * Checks the instance's INI file to figure out what the instance's type is first.
+	 * \param inst Pointer to store the loaded instance in.
+	 * \param instDir The instance's directory.
+	 * \return An InstLoadError error code.
+	 * - NotAnInstance if the given instance directory isn't a valid instance.
+	 */
+	InstLoadError loadInstance(BaseInstance *&inst, const QString &instDir);
+	
+private:
+	InstanceFactory();
+	
+	static InstanceFactory loader;
+};