Simplify DLL hook mechanism

This change deletes the GetProcAddress hook and exports symbols
corresponding to the hooked functions from each hook DLL instead;
we stop at redirecting LoadLibrary/GetModuleHandle calls to the
hook DLL. This simplified approach has less hidden magic going on
behind the scenes and is more readily composable (i.e. a hook DLL
can export redirect symbols for more than one dynamically-loaded
DLL).

chunihook/chunihook.def

@@ -1,3 +1,8 @@
 LIBRARY chunihook
 
 EXPORTS
+    Direct3DCreate9
+    amDllVideoClose @2
+    amDllVideoGetVBiosVersion @4
+    amDllVideoOpen @1
+    amDllVideoSetResolution @3

chunihook/dllmain.c

@@ -60,7 +60,7 @@ static DWORD CALLBACK chuni_pre_startup(void)
 
     /* Hook Win32 APIs */
 
-    gfx_hook_init(&chuni_hook_cfg.gfx);
+    gfx_hook_init(&chuni_hook_cfg.gfx, chuni_hook_mod);
     serial_hook_init();
 
     /* Initialize emulation hooks */