Make stepper shutdown after inactivity dependent

Make stepper shutdown after inactivity dependent on a new set of
#defines.
DISABLE_INACTIV_X
DISABLE_INACTIV_Y
DISABLE_INACTIV_Z
DISABLE_INACTIV_E

And make exemplaric Configuration.
Names can be discussed.

This makes the disabling of the steppers independent from the DISABLE_?
settings witch shut down the steppers immediately.

Marlin/Configuration.h

@@ -349,7 +349,7 @@ const bool Z_MIN_PROBE_ENDSTOP_INVERTING = false; // set to true to invert the l
 #define Z_ENABLE_ON 0
 #define E_ENABLE_ON 0 // For all extruders
 
-// Disables axis when it's not being used.
+// Disables axis stepper immediately  when it's not being used.
 // WARNING: When motors turn off there is a chance of losing position accuracy!
 #define DISABLE_X false
 #define DISABLE_Y false

Marlin/Configuration_adv.h

@@ -52,7 +52,7 @@
  * The maximum buffered steps/sec of the extruder motor is called "se".
  * Start autotemp mode with M109 S<mintemp> B<maxtemp> F<factor>
  * The target temperature is set to mintemp+factor*se[steps/sec] and is limited by
- * mintemp and maxtemp. Turn this off by excuting M109 without F*
+ * mintemp and maxtemp. Turn this off by executing M109 without F*
  * Also, if the temperature is set to a value below mintemp, it will not be changed by autotemp.
  * On an Ultimaker, some initial testing worked with M109 S215 B260 F1 in the start.gcode
  */
@@ -232,7 +232,13 @@
 #define INVERT_E_STEP_PIN false
 
 // Default stepper release if idle. Set to 0 to deactivate.
-#define DEFAULT_STEPPER_DEACTIVE_TIME 60
+// Steppers will shut down DEFAULT_STEPPER_DEACTIVE_TIME seconds after the last move when DISABLE_INACTIV_? is true.
+// Time can be set by M18 and M84.
+#define DEFAULT_STEPPER_DEACTIVE_TIME 120
+#define DISABLE_INACTIVE_X true
+#define DISABLE_INACTIVE_Y true
+#define DISABLE_INACTIVE_Z true  // set to false if the nozzle will fall down on your printed part when print has finished.
+#define DISABLE_INACTIVE_E true
 
 #define DEFAULT_MINIMUMFEEDRATE       0.0     // minimum feedrate
 #define DEFAULT_MINTRAVELFEEDRATE     0.0

Marlin/Marlin_main.cpp

@@ -6956,16 +6956,16 @@ void manage_inactivity(bool ignore_stepper_queue/*=false*/) {
 
   if (stepper_inactive_time && ms > previous_cmd_ms + stepper_inactive_time
       && !ignore_stepper_queue && !blocks_queued()) {
-    #if DISABLE_X == true
+    #if DISABLE_INACTIV_X == true
       disable_x();
     #endif
-    #if DISABLE_Y == true
+    #if DISABLE_INACTIV_Y == true
       disable_y();
     #endif
-    #if DISABLE_Z == true
+    #if DISABLE_INACTIV_Z == true
       disable_z();
     #endif
-    #if DISABLE_E == true
+    #if DISABLE_INACTIV_E == true
       disable_e0();
       disable_e1();
       disable_e2();