options: Add wide_links config option.

In some environments, it makes sense to validate that symlink destinations
remain inside user-defined media_dirs.  Make this behavior configurable.

minidlna.c

@@ -750,6 +750,10 @@ init(int argc, char **argv)
 			if (strtobool(ary_options[i].value))
 				SETFLAG(MERGE_MEDIA_DIRS_MASK);
 			break;
+		case WIDE_LINKS:
+			if (strtobool(ary_options[i].value))
+				SETFLAG(WIDE_LINKS_MASK);
+			break;
 		default:
 			DPRINTF(E_ERROR, L_GENERAL, "Unknown option in file %s\n",
 				optionsfile);