G10/G11 bugfixes

Previous version was broken by using G92 E0 between retract and recover.

Marlin/Marlin_main.cpp

         destination[Y_AXIS]=current_position[Y_AXIS];
         destination[Z_AXIS]=current_position[Z_AXIS];
         current_position[Z_AXIS]-=retract_zlift;
-        destination[E_AXIS]=current_position[E_AXIS]-retract_length/volumetric_multiplier[active_extruder];
+        destination[E_AXIS]=current_position[E_AXIS];
+        current_position[E_AXIS]+=retract_length/volumetric_multiplier[active_extruder];
+        plan_set_e_position(current_position[E_AXIS]);
         float oldFeedrate = feedrate;
         feedrate=retract_feedrate;
         retracted=true;
         destination[Y_AXIS]=current_position[Y_AXIS];
         destination[Z_AXIS]=current_position[Z_AXIS];
         current_position[Z_AXIS]+=retract_zlift;
-        destination[E_AXIS]=current_position[E_AXIS]+(retract_length+retract_recover_length)/volumetric_multiplier[active_extruder]; 
+        destination[E_AXIS]=current_position[E_AXIS];
+        current_position[E_AXIS]-=(retract_length+retract_recover_length)/volumetric_multiplier[active_extruder]; 
+        plan_set_e_position(current_position[E_AXIS]);
         float oldFeedrate = feedrate;
         feedrate=retract_recover_feedrate;
         retracted=false;