Custom path support (#1333)

also including:
* getting rid of shitty strings
* all new, cleaner ROM handling code
* base for DSi savestates
* GBA slot addons (for now, memory cart)

src/DSi_Camera.h

@@ -28,6 +28,8 @@ public:
     static void DeInit();
     static void Reset();
 
+    static void DoSavestate(Savestate* file);
+
     static void IRQ(u32 param);
     static void RequestFrame(u32 cam);
 
@@ -36,6 +38,8 @@ public:
     DSi_Camera(u32 num);
     ~DSi_Camera();
 
+    void DoCamSavestate(Savestate* file);
+
     void ResetCam();
     bool IsActivated();