GH-796 Icon theme loading workaround

Replacing the Qt machinery with other Qt machinery under our control

MultiMC.h

@@ -5,6 +5,7 @@
 #include "logger/QsLog.h"
 #include "logger/QsLogDest.h"
 #include <QFlag>
+#include <QIcon>
 
 class MinecraftVersionList;
 class LWJGLVersionList;
@@ -72,6 +73,10 @@ public:
 
 	std::shared_ptr<IconList> icons();
 
+	QIcon getThemedIcon(const QString& name);
+
+	void setIconTheme(const QString& name);
+
 	Status status()
 	{
 		return m_status;