new method for message for making KILLED message visible

The cli(); at the start of the kill() function also stops the internal
arduino timer which stops updating of millis() which prevents the
display of the "KILLED." message.
The new function updates the display directly without checking any
timers.

Marlin/Marlin.pde

   if(PS_ON_PIN > -1) pinMode(PS_ON_PIN,INPUT);
   SERIAL_ERROR_START;
   SERIAL_ERRORLNPGM(MSG_ERR_KILLED);
-  LCD_MESSAGEPGM(MSG_KILLED);
+  LCD_ALERTMESSAGEPGM(MSG_KILLED);
   suicide();
   while(1); // Wait for reset
 }

Marlin/ultralcd.h

   #define LCD_INIT lcd_init();
   #define LCD_MESSAGE(x) lcd_status(x);
   #define LCD_MESSAGEPGM(x) lcd_statuspgm(MYPGM(x));
+  #define LCD_ALERTMESSAGEPGM(x) lcd_alertstatuspgm(MYPGM(x));
   #define LCD_STATUS lcd_status()
 #else //no lcd
   #define LCD_INIT
   #define LCD_STATUS
   #define LCD_MESSAGE(x)
   #define LCD_MESSAGEPGM(x)
+  #define LCD_ALERTMESSAGEPGM(x)
   FORCE_INLINE void lcd_status() {};
 
   #define CLICKED false
 #endif 
   
 void lcd_statuspgm(const char* message);
+void lcd_alertstatuspgm(const char* message);
   
 char *ftostr3(const float &x);
 char *itostr2(const uint8_t &x);

Marlin/ultralcd.pde

   *target=0;
 }
 
+void lcd_alertstatuspgm(const char* message)
+{
+  lcd_statuspgm(message); 
+  menu.showStatus(); 
+}
+
 FORCE_INLINE void clear()
 {
   lcd.clear();