The safe_delay() is now globaly accessible

Marlin/Marlin.h

   #endif
 #endif
 
+void safe_delay(uint16_t del);
+
 #endif //MARLIN_H

Marlin/Marlin_main.cpp

   lcd_init();
   #if ENABLED(SHOW_BOOTSCREEN)
     #if ENABLED(DOGLCD)
-      delay(BOOTSCREEN_TIMEOUT);
+      safe_delay(BOOTSCREEN_TIMEOUT);
     #elif ENABLED(ULTRA_LCD)
       bootscreen();
       lcd_init();

Marlin/ultralcd_implementation_hitachi_HD44780.h

     lcd.setCursor(indent, 2); lcd.print('\x02'); lcd_printPGM(PSTR( "------" ));  lcd.print('\x03');
   }
 
-  void safe_delay(uint16_t del){
-    while (del > 50) {
-      del -= 50;
-      delay(50);
-      thermalManager.manage_heater();
-    }
-    delay(del);
-  }
-
   void bootscreen() {
     byte top_left[8] = {
       B00000,

Marlin/utility.cpp

+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "Marlin.h"
+#include "temperature.h"
+
+void safe_delay(uint16_t ms) {
+  while (ms > 50) {
+    ms -= 50;
+    delay(50);
+    thermalManager.manage_heater();
+  }
+  delay(ms);
+}