(svn r8605) -Codechange: [OSX] changed all objective C to objective C++

This will permanently solve the issue where compilation on OSX broke because C++ code was added to some header files

   -Note: (important if you develop mac specific code)
   taken from http://developer.apple.com/releasenotes/Cocoa/Objective-C++.html           
    gdb lacks an integrated C++ with Objective-C parser. This means that gdb won't be able to evaluate expressions that contain both C++ and Objective-C constructs.
    gdb assumes that the language for ".mm" files is C++.
    you can change it to objective C by typing: (gdb) set language objc 
    Mixing C++ and objective C has some limitation (see link for all of them)

src/video/cocoa_v.h

@@ -5,22 +5,9 @@
 
 #include "../hal.h"
 
-#ifndef __cplusplus
-/* Really ugly workaround
- * It should be solved right as soon as possible */
-typedef uint32 SpriteID;
-#endif //__cplusplus
-
+#include "../openttd.h"
 #include "../gfx.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif //__cplusplus
-
 extern const HalVideoDriver _cocoa_video_driver;
 
-#ifdef __cplusplus
-} // extern "C"
-#endif //__cplusplus
-
 #endif