Fix: Long menu entries (>14 or >18 chars) caused overrun in hitachi display implementation

Marlin/ultralcd_implementation_hitachi_HD44780.h

   #endif
     lcd.setCursor(0, row);
     lcd.print(pre_char);
-    while((c = pgm_read_byte(pstr)) != '\0')
+    while( ((c = pgm_read_byte(pstr)) != '\0') && (n>0) )
     {
         lcd.print(c);
         pstr++;
   #endif
     lcd.setCursor(0, row);
     lcd.print(pre_char);
-    while((c = pgm_read_byte(pstr)) != '\0')
+    while( ((c = pgm_read_byte(pstr)) != '\0') && (n>0) )
     {
         lcd.print(c);
         pstr++;
   #endif
     lcd.setCursor(0, row);
     lcd.print(pre_char);
-    while((c = pgm_read_byte(pstr)) != '\0')
+    while( ((c = pgm_read_byte(pstr)) != '\0') && (n>0) )
     {
         lcd.print(c);
         pstr++;
         filename = longFilename;
         longFilename[LCD_WIDTH-1] = '\0';
     }
-    while((c = *filename) != '\0')
+    while( ((c = *filename) != '\0') && (n>0) )
     {
         lcd.print(c);
         filename++;
         filename = longFilename;
         longFilename[LCD_WIDTH-1] = '\0';
     }
-    while((c = *filename) != '\0')
+    while( ((c = *filename) != '\0') && (n>0) )
     {
         lcd.print(c);
         filename++;
         filename = longFilename;
         longFilename[LCD_WIDTH-2] = '\0';
     }
-    while((c = *filename) != '\0')
+    while( ((c = *filename) != '\0') && (n>0) )
     {
         lcd.print(c);
         filename++;
         filename = longFilename;
         longFilename[LCD_WIDTH-2] = '\0';
     }
-    while((c = *filename) != '\0')
+    while( ((c = *filename) != '\0') && (n>0) )
     {
         lcd.print(c);
         filename++;