Huge compile performance refactor

lib/x11/WindowXlib.cpp

@@ -10,10 +10,10 @@
 #endif
 
 #include <limits.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdint.h>
-#include <string.h>
+#include <cstdlib>
+#include <cstdio>
+#include <cstdint>
+#include <cstring>
 
 #include <thread>
 #include <mutex>