Some minor changes on code style. And a bugfix where the counters for positioning in the stepper where wrong depending on compiler settings. (Caused strange values to reported back with M114 and endstop triggers). Also fixed compiling with FWRETRACT enabled.

Marlin/Marlin.h

 
 extern float homing_feedrate[];
 extern bool axis_relative_modes[];
+extern int feedmultiply;
+extern int extrudemultiply; // Sets extrude multiply factor (in percent)
 extern float current_position[NUM_AXIS] ;
 extern float add_homeing[3];
 extern float min_pos[3];
 extern float max_pos[3];
-extern unsigned char FanSpeed;
+extern int fanSpeed;
+
+#ifdef FWRETRACT
+extern bool autoretract_enabled;
+extern bool retracted;
+extern float retract_length, retract_feedrate, retract_zlift;
+extern float retract_recover_length, retract_recover_feedrate;
+#endif
 
 extern unsigned long starttime;
 extern unsigned long stoptime;

Marlin/Marlin_main.cpp

 #endif
 float homing_feedrate[] = HOMING_FEEDRATE;
 bool axis_relative_modes[] = AXIS_RELATIVE_MODES;
-volatile int feedmultiply=100; //100->1 200->2
+int feedmultiply=100; //100->1 200->2
 int saved_feedmultiply;
-volatile bool feedmultiplychanged=false;
-volatile int extrudemultiply=100; //100->1 200->2
+int extrudemultiply=100; //100->1 200->2
 float current_position[NUM_AXIS] = { 0.0, 0.0, 0.0, 0.0 };
 float add_homeing[3]={0,0,0};
 float min_pos[3] = { X_MIN_POS, Y_MIN_POS, Z_MIN_POS };
 float max_pos[3] = { X_MAX_POS, Y_MAX_POS, Z_MAX_POS };
 uint8_t active_extruder = 0;
-unsigned char FanSpeed=0;
+int fanSpeed=0;
 
 #ifdef FWRETRACT
   bool autoretract_enabled=true;
     #if FAN_PIN > -1
       case 106: //M106 Fan On
         if (code_seen('S')){
-           FanSpeed=constrain(code_value(),0,255);
+           fanSpeed=constrain(code_value(),0,255);
         }
         else {
-          FanSpeed=255;			
+          fanSpeed=255;			
         }
         break;
       case 107: //M107 Fan Off
-        FanSpeed = 0;
+        fanSpeed = 0;
         break;
     #endif //FAN_PIN
 
       if(code_seen('S')) 
       {
         feedmultiply = code_value() ;
-        feedmultiplychanged=true;
       }
     }
     break;

Marlin/cardreader.h

   char* diveDirName;
   void lsDive(const char *prepend,SdFile parent);
 };
+extern CardReader card;
 #define IS_SD_PRINTING (card.sdprinting)
 
 #else

Marlin/planner.cpp

 static float previous_speed[4]; // Speed of previous path line segment
 static float previous_nominal_speed; // Nominal speed of previous path line segment
 
-extern volatile int extrudemultiply; // Sets extrude multiply factor (in percent)
-
 #ifdef AUTOTEMP
 float autotemp_max=250;
 float autotemp_min=210;
   else
   {
     #if FAN_PIN > -1
-    if (FanSpeed != 0){
-      analogWrite(FAN_PIN,FanSpeed); // If buffer is empty use current fan speed
+    if (fanSpeed != 0){
+      analogWrite(FAN_PIN,fanSpeed); // If buffer is empty use current fan speed
     }
     #endif
   }
     disable_e2(); 
   }
 #if FAN_PIN > -1
-  if((FanSpeed == 0) && (fan_speed ==0))
+  if((fanSpeed == 0) && (fan_speed ==0))
   {
     analogWrite(FAN_PIN, 0);
   }
 
-  if (FanSpeed != 0 && tail_fan_speed !=0)
+  if (fanSpeed != 0 && tail_fan_speed !=0)
   {
     analogWrite(FAN_PIN,tail_fan_speed);
   }
     return; 
   }
 
-  block->fan_speed = FanSpeed;
+  block->fan_speed = fanSpeed;
 
   // Compute direction bits for this block 
   block->direction_bits = 0;

Marlin/stepper.cpp

 static bool check_endstops = true;
 
 volatile long count_position[NUM_AXIS] = { 0, 0, 0, 0};
-volatile char count_direction[NUM_AXIS] = { 1, 1, 1, 1};
+volatile signed char count_direction[NUM_AXIS] = { 1, 1, 1, 1};
 
 //===========================================================================
 //=============================functions         ============================

Marlin/temperature.cpp

     }
   #endif
 
-  if(heater_ttbl_map[e] != 0)
+  if(heater_ttbl_map[e] != NULL)
   {
     float celsius = 0;
     byte i;