Various minor updates and variable definition corrections. Removed deprecated acceleration manager.

- Removed deprecated acceleration manager (non-functional since v0.7b)
- Updated variable types and function headers. - Updated stepper
interrupt to ISR() from SIGNAL()+sei(). - General code cleanup.

nuts_bolts.c

@@ -1,3 +1,23 @@
+/*
+  nuts_bolts.c - Shared functions
+  Part of Grbl
+
+  Copyright (c) 2009-2011 Simen Svale Skogsrud
+
+  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/>.
+*/
+
 #include "nuts_bolts.h"
 #include <stdint.h>
 #include <stdlib.h>