Changed kinematics API and implementations (corexy and wallplotter) to allow backlash compensation. Ref [ESP32 issue 25](https://github.com/grblHAL/ESP32/issues/25).

Fixed feed rate handling for corexy kinematics. Ref issue #147.
Fixed tool table/tool change bugs. Ref. [ioSender issue 228](https://github.com/terjeio/ioSender/issues/228).

planner.h

@@ -3,7 +3,7 @@
 
   Part of grblHAL
 
-  Copyright (c) 2019-2021 Terje Io
+  Copyright (c) 2019-2022 Terje Io
   Copyright (c) 2011-2016 Sungeun K. Jeon for Gnea Research LLC
   Copyright (c) 2009-2011 Simen Svale Skogsrud
 
@@ -132,6 +132,9 @@ float plan_get_exec_block_exit_speed_sqr();
 // Called by main program during planner calculations and step segment buffer during initialization.
 float plan_compute_profile_nominal_speed(plan_block_t *block);
 
+// Get the planner position vectors.
+float *plan_get_position (void);
+
 // Reset the planner position vector (in steps)
 void plan_sync_position();