logic: add name delimiter to NameHierarchy

* NameHierarchy now looks like this: <delimiter>\tm<all the rest>
* made new baseclasses for SettingsMigration and SettingsMigrator
* Use the migration system for SqliteBookmarkStorage as well

src/lib/utility/migration/Migration.h

@@ -0,0 +1,17 @@
+#ifndef MIGRATION_H
+#define MIGRATION_H
+
+template <typename MigratableType>
+class Migration
+{
+public:
+	virtual ~Migration();
+	virtual void apply(MigratableType* migratable) const = 0;
+};
+
+template <typename MigratableType>
+Migration<MigratableType>::~Migration()
+{
+}
+
+#endif // MIGRATION_H

src/lib/utility/migration/Migrator.h

@@ -0,0 +1,87 @@
+#ifndef MIGRATOR_H
+#define MIGRATOR_H
+
+#include <map>
+#include <memory>
+
+#include "utility/migration/Migration.h"
+
+template <typename MigratableType>
+class Migrator
+{
+public:
+	virtual ~Migrator();
+
+	void addMigration(size_t targetVersion, std::shared_ptr<Migration<MigratableType>> migration);
+
+	bool willMigrate(const MigratableType* migratable, size_t targetVersion) const;
+	bool migrate(MigratableType* migratable, size_t targetVersion) const;
+
+private:
+	typedef std::multimap<size_t, std::shared_ptr<Migration<MigratableType>>> MigrationMap;
+	MigrationMap m_migrations;
+};
+
+
+template <typename MigratableType>
+Migrator<MigratableType>::~Migrator()
+{
+}
+
+template <typename MigratableType>
+void Migrator<MigratableType>::addMigration(size_t targetVersion, std::shared_ptr<Migration<MigratableType>> migration)
+{
+	if (migration)
+	{
+		m_migrations.emplace(targetVersion, migration);
+	}
+}
+
+template <typename MigratableType>
+bool Migrator<MigratableType>::willMigrate(const MigratableType* migratable, size_t targetVersion) const
+{
+	size_t sourceVersion = migratable->getVersion();
+
+	if (sourceVersion < targetVersion)
+	{
+		for (; sourceVersion <= targetVersion; sourceVersion++)
+		{
+			std::pair<MigrationMap::const_iterator, MigrationMap::const_iterator> ret;
+			ret = m_migrations.equal_range(sourceVersion);
+
+			for (MigrationMap::const_iterator it = ret.first; it != ret.second; it++)
+			{
+				return true;
+			}
+		}
+	}
+
+	return false;
+}
+
+template <typename MigratableType>
+bool Migrator<MigratableType>::migrate(MigratableType* migratable, size_t targetVersion) const
+{
+	size_t sourceVersion = migratable->getVersion();
+
+	if (sourceVersion < targetVersion)
+	{
+		for (; sourceVersion <= targetVersion; sourceVersion++)
+		{
+			std::pair<MigrationMap::const_iterator, MigrationMap::const_iterator> ret;
+			ret = m_migrations.equal_range(sourceVersion);
+
+			for (MigrationMap::const_iterator it = ret.first; it != ret.second; it++)
+			{
+				it->second->apply(migratable);
+			}
+		}
+
+		migratable->setVersion(targetVersion);
+		return true;
+	}
+
+	return false;
+}
+
+#endif // MIGRATOR_H