patch #7165 Add support for bitbanging GPIO lines using the Linux sysf GPIO interface

* doc/avrdude.texi,avrdude.1: added doc for linuxgpio 
	* avrdude.conf.in: added template for linuxgpio programmer
	* config_gram.y: pin numbers restricted to [PIN_MIN, PIN_MAX]
	* pindefs.h: added PIN_MIN, PIN_MAX, removed unused LED_ON/OFF
	* configure.ac: configure option enable-linuxgpio, print of enabled options
	* linuxgpio.[ch]: new source for linuxgpio programmer
	* Makefile.am: added linuxgpio to sources list
	* pgm_type.c: added linuxgpio to programmer types list

git-svn-id: svn://svn.savannah.nongnu.org/avrdude/trunk/avrdude@1132 81a1dc3b-b13d-400b-aceb-764788c761c2

linuxgpio.h

@@ -0,0 +1,36 @@
+/*
+ * avrdude - A Downloader/Uploader for AVR device programmers
+ * Copyright (C) 2013 Radoslav Kolev <radoslav@kolev.info>
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/* $Id: par.h 722 2007-01-24 22:43:46Z joerg_wunsch $ */
+
+#ifndef linuxgpio_h
+#define linuxgpio_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern const char linuxgpio_desc[];
+void linuxgpio_initpgm        (PROGRAMMER * pgm);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif