Added new menu items under the prepare submenu.

Instead of a single pre-heat, now there is pre-heat ABS and PLA options
Added defines to the configuration file to adjust preheat temperatures for both

Marlin/Configuration_adv.h

@@ -74,7 +74,7 @@
 #define X_HOME_RETRACT_MM 5 
 #define Y_HOME_RETRACT_MM 5 
 #define Z_HOME_RETRACT_MM 1 
-#define QUICK_HOME  //if this is defined, if both x and y are to be homed, a diagonal move will be performed initially.
+//#define QUICK_HOME  //if this is defined, if both x and y are to be homed, a diagonal move will be performed initially.
 
 #define AXIS_RELATIVE_MODES {false, false, false, false}
 
@@ -152,7 +152,7 @@ const int dropsegments=5; //everything with less than this number of steps will
 // You can get round this by connecting a push button or single throw switch to the pin defined as SDCARDCARDDETECT 
 // in the pins.h file.  When using a push button pulling the pin to ground this will need inverted.  This setting should
 // be commented out otherwise
-//#define SDCARDDETECTINVERTED 
+#define SDCARDDETECTINVERTED 
 
 //===========================================================================
 //=============================Buffers           ============================