First xcb implementation

Former-commit-id: 483522109b8b63fa80b9152b04bca79a65809d4d

include/Nazara/Utility/WindowHandle.hpp

@@ -13,8 +13,9 @@
 // http://msdn.microsoft.com/en-us/library/aa383751(v=vs.85).aspx
 typedef void* NzWindowHandle;
 #elif defined(NAZARA_PLATFORM_LINUX)
+#include <xcb/xcb.h>
 // http://en.wikipedia.org/wiki/Xlib#Data_types
-typedef unsigned long NzWindowHandle;
+using NzWindowHandle = xcb_window_t;
 #else
 	#error Lack of implementation: WindowHandle
 #endif