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

@@ -447,6 +447,8 @@ const bool Z_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of
 //#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
@@ -532,6 +534,21 @@ const bool Z_MAX_ENDSTOP_INVERTING = true; // set to true to invert the logic of
   #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