merge doublemelon (#2067)

non-exhaustive (but exhausting) list of changes:

* base laid for multiple window support, but will likely require more work to work correctly
* encapsulation of frontend state for proper multi-instance support
* (JIT still needs a fix for the NDS::Current workaround but we can get there later)
* new, more flexible configuration system

src/frontend/qt_sdl/InputConfig/InputConfigDialog.h

@@ -24,6 +24,7 @@
 #include <initializer_list>
 
 #include "Config.h"
+#include "EmuInstance.h"
 
 static constexpr int keypad_num = 12;
 
@@ -89,6 +90,8 @@ public:
     explicit InputConfigDialog(QWidget* parent);
     ~InputConfigDialog();
 
+    SDL_Joystick* getJoystick();
+
     static InputConfigDialog* currentDlg;
     static InputConfigDialog* openDlg(QWidget* parent)
     {
@@ -123,9 +126,12 @@ private:
 
     Ui::InputConfigDialog* ui;
 
+    EmuInstance* emuInstance;
+
     int keypadKeyMap[12], keypadJoyMap[12];
     int addonsKeyMap[hk_addons.size()], addonsJoyMap[hk_addons.size()];
     int hkGeneralKeyMap[hk_general.size()], hkGeneralJoyMap[hk_general.size()];
+    int joystickID;
 };