Silenced warnings about -Wchar-subscripts, added /usr/local for NetBSD

acinclude.m4

@@ -1,7 +1,7 @@
 AC_DEFUN([LIBBURNIA_SET_FLAGS],
 [
 case $target_os in
-freebsd*)
+freebsd* | netbsd*)
         LDFLAGS="$LDFLAGS -L/usr/local/lib"
         CPPFLAGS="$CPPFLAGS -I/usr/local/include"
         ;;

configure.ac

@@ -339,7 +339,7 @@ if test x$enable_debug != xyes; then
     CFLAGS="-DNDEBUG $CFLAGS"
 else
     if test x$GCC = xyes; then
-        CFLAGS="-g -pedantic -Wall -Wextra -Wno-unused-parameter $CFLAGS"
+        CFLAGS="-g -pedantic -Wall -Wextra -Wno-unused-parameter -Wno-char-subscripts $CFLAGS"
     fi
     CFLAGS="-DDEBUG $CFLAGS"
 fi