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/WifiAP.h

@@ -28,7 +28,7 @@ class Wifi;
 class WifiAP
 {
 public:
-    WifiAP(Wifi* client);
+    WifiAP(Wifi* client, void* userdata);
     ~WifiAP();
     void Reset();
 
@@ -44,6 +44,7 @@ public:
 
 private:
     Wifi* Client;
+    void* UserData;
 
     u64 USCounter;