File re-organization. New Makefile.

- Re-organized source code files into a ‘grbl’ directory to lessen one
step in compiling Grbl through the Arduino IDE.

- Added an ‘examples’ directory with an upload .INO sketch to further
simplify compiling and uploading Grbl via the Arduino IDE.

- Updated the Makefile with regard to the source code no longer being
in the root directory. All files generated by compiling is placed in a
separate ‘build’ directory to keep things tidy. The makefile should
operate in the same way as it did before.

motion_control.h

@@ -1,72 +0,0 @@
-/*
-  motion_control.h - high level interface for issuing motion commands
-  Part of Grbl v0.9
-
-  Copyright (c) 2012-2015 Sungeun K. Jeon
-  
-  Grbl is free software: you can redistribute it and/or modify
-  it under the terms of the GNU General Public License as published by
-  the Free Software Foundation, either version 3 of the License, or
-  (at your option) any later version.
-
-  Grbl is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-  GNU General Public License for more details.
-
-  You should have received a copy of the GNU General Public License
-  along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
-*/
-/* 
-  This file is based on work from Grbl v0.8, distributed under the 
-  terms of the MIT-license. See COPYING for more details.  
-    Copyright (c) 2009-2011 Simen Svale Skogsrud
-    Copyright (c) 2011-2012 Sungeun K. Jeon
-*/  
-
-#ifndef motion_control_h
-#define motion_control_h
-
-
-#define HOMING_CYCLE_LINE_NUMBER -1
-
-// Execute linear motion in absolute millimeter coordinates. Feed rate given in millimeters/second
-// unless invert_feed_rate is true. Then the feed_rate means that the motion should be completed in
-// (1 minute)/feed_rate time.
-#ifdef USE_LINE_NUMBERS
-void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate, int32_t line_number);
-#else
-void mc_line(float *target, float feed_rate, uint8_t invert_feed_rate);
-#endif
-
-// Execute an arc in offset mode format. position == current xyz, target == target xyz, 
-// offset == offset from current xyz, axis_XXX defines circle plane in tool space, axis_linear is
-// the direction of helical travel, radius == circle radius, is_clockwise_arc boolean. Used
-// for vector transformation direction.
-#ifdef USE_LINE_NUMBERS
-void mc_arc(float *position, float *target, float *offset, float radius, float feed_rate, 
-  uint8_t invert_feed_rate, uint8_t axis_0, uint8_t axis_1, uint8_t axis_linear, uint8_t is_clockwise_arc, int32_t line_number);
-#else
-void mc_arc(float *position, float *target, float *offset, float radius, float feed_rate,
-  uint8_t invert_feed_rate, uint8_t axis_0, uint8_t axis_1, uint8_t axis_linear, uint8_t is_clockwise_arc);
-#endif
-  
-// Dwell for a specific number of seconds
-void mc_dwell(float seconds);
-
-// Perform homing cycle to locate machine zero. Requires limit switches.
-void mc_homing_cycle();
-
-// Perform tool length probe cycle. Requires probe switch.
-#ifdef USE_LINE_NUMBERS
-void mc_probe_cycle(float *target, float feed_rate, uint8_t invert_feed_rate, uint8_t is_probe_away,
-  uint8_t is_no_error, int32_t line_number);
-#else
-void mc_probe_cycle(float *target, float feed_rate, uint8_t invert_feed_rate, uint8_t is_probe_away,
-  uint8_t is_no_error);
-#endif
-
-// Performs system reset. If in motion state, kills all motion and sets system alarm.
-void mc_reset();
-
-#endif