GH-992 Add a transaction/locking mechanism to settings objects

This can cut the FTB loading by ~66% - worth it, but not ideal.
Real solution will have to be implemented later.

application/pages/InstanceSettingsPage.cpp

@@ -14,7 +14,7 @@
 InstanceSettingsPage::InstanceSettingsPage(BaseInstance *inst, QWidget *parent)
 	: QWidget(parent), ui(new Ui::InstanceSettingsPage), m_instance(inst)
 {
-	m_settings = &(inst->settings());
+	m_settings = inst->settings();
 	ui->setupUi(this);
 	loadSettings();
 }