support for scripts in $HOME/.openocd

Add $HOME/.openocd as the first default script search directory, allowing
the user to override the standard scripts.

Update the user guide with information on where OpenOCD expects to find
configuration files and scripts. Also fixed some minor formatting issues.

Add entry to NEWS as well.

Signed-off-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

src/helper/options.c

@@ -101,7 +101,22 @@ static void add_default_dirs(void)
 	 * listed last in the built-in search order, so the user can
 	 * override these scripts with site-specific customizations.
 	 */
-	/// @todo Implement @c add_script_search_dir("${HOME}/.openocd").
+
+	const char *home = getenv("HOME");
+
+	if (home) 
+	{
+		char *path;
+
+		path = alloc_printf("%s/.openocd", home);
+
+		if (path) 
+	        {
+			add_script_search_dir(path);
+			free(path);
+		}
+	}
+
 	add_script_search_dir(PKGDATADIR "/site");
 	add_script_search_dir(PKGDATADIR "/scripts");
 #endif