Improved support for panelolu2 encoder and buzzer

I added #define for LCD_FEEDBACK_FREQUENCY_HZ and
LCD_FEEDBACK_FREQUENCY_DURATION_MS  which is used to alter the default
buzzer sound.

When selecting Panelolu2 in configuration.h:
- it automatically sets the correct ENCODER_PULSES_PER_STEP and
ENCODER_STEPS_PER_MENU_ITEM.
- if LCD_USE_I2C_BUZZER is defined it will also set the default
LCD_FEEDBACK_FREQUENCY_HZ and LCD_FEEDBACK_FREQUENCY_DURATION_MS

When selecting the sanguinololu 1284p the following is true:
- its now enables  LARGE_FLASH
- It enables the gcode M300 when the panelolu2 LCD_USE_I2C_BUZZER is
defined

Marlin/Configuration.h

 //#define ENCODER_STEPS_PER_MENU_ITEM 5 // Set according to ENCODER_PULSES_PER_STEP or your liking
 //#define ULTIMAKERCONTROLLER //as available from the ultimaker online store.
 //#define ULTIPANEL  //the ultipanel as on thingiverse
+//#define LCD_FEEDBACK_FREQUENCY_HZ 1000	// this is the tone frequency the buzzer plays when on UI feedback. ie Screen Click
+//#define LCD_FEEDBACK_FREQUENCY_DURATION_MS 100 // the duration the buzzer plays the UI feedback sound. ie Screen Click
 
 // The MaKr3d Makr-Panel with graphic controller and SD support
 // http://reprap.org/wiki/MaKr3d_MaKrPanel
   #define LCD_USE_I2C_BUZZER //comment out to disable buzzer on LCD
   #define NEWPANEL
   #define ULTIPANEL
+  
+  #ifndef ENCODER_PULSES_PER_STEP
+	#define ENCODER_PULSES_PER_STEP 4
+  #endif 
+
+  #ifndef ENCODER_STEPS_PER_MENU_ITEM
+	#define ENCODER_STEPS_PER_MENU_ITEM 1
+  #endif 
+  
+  
+  #ifdef LCD_USE_I2C_BUZZER
+	#define LCD_FEEDBACK_FREQUENCY_HZ 1000
+	#define LCD_FEEDBACK_FREQUENCY_DURATION_MS 100
+  #endif
+  
 #endif
 
 // Panucatt VIKI LCD with status LEDs, integrated click & L/R/U/P buttons, separate encoder inputs

Marlin/Marlin_main.cpp

       break;
     #endif // NUM_SERVOS > 0
 
-    #if LARGE_FLASH == true && ( BEEPER > 0 || defined(ULTRALCD) )
+    #if (LARGE_FLASH == true && ( BEEPER > 0 || defined(ULTRALCD) || defined(LCD_USE_I2C_BUZZER)))
     case 300: // M300
     {
       int beepS = code_seen('S') ? code_value() : 110;
           delay(beepP);
           noTone(BEEPER);
         #elif defined(ULTRALCD)
-          lcd_buzz(beepS, beepP);
+		  lcd_buzz(beepS, beepP);
+		#elif defined(LCD_USE_I2C_BUZZER)
+		  lcd_buzz(beepP, beepS);
         #endif
       }
       else
             WRITE(BEEPER,LOW);
             delay(3);
           #else
-            lcd_buzz(1000/6,100);
+			#if !defined(LCD_FEEDBACK_FREQUENCY_HZ) || !defined(LCD_FEEDBACK_FREQUENCY_DURATION_MS)
+              lcd_buzz(1000/6,100);
+			#else
+			  lcd_buzz(LCD_FEEDBACK_FREQUENCY_DURATION_MS,LCD_FEEDBACK_FREQUENCY_HZ);
+			#endif
           #endif
           }
         }

Marlin/pins.h

 #undef MOTHERBOARD
 #define MOTHERBOARD 6
 #define SANGUINOLOLU_V_1_2
+
+#if defined(__AVR_ATmega1284P__)
+	#define LARGE_FLASH true
+#endif
 #endif
 #if MOTHERBOARD == 6
 #define KNOWN_BOARD 1

Marlin/ultralcd_implementation_hitachi_HD44780.h

 static void lcd_implementation_quick_feedback()
 {
 #ifdef LCD_USE_I2C_BUZZER
-    lcd.buzz(60,1000/6);
+	#if !defined(LCD_FEEDBACK_FREQUENCY_HZ) || !defined(LCD_FEEDBACK_FREQUENCY_DURATION_MS)
+	  lcd_buzz(1000/6,100);
+	#else
+	  lcd_buzz(LCD_FEEDBACK_FREQUENCY_DURATION_MS,LCD_FEEDBACK_FREQUENCY_HZ);
+	#endif
 #elif defined(BEEPER) && BEEPER > -1
     SET_OUTPUT(BEEPER);
     for(int8_t i=0;i<10;i++)