build: Use modern Autoconf check for types.
* common/types.h: Use HAVE_TYPE_BYTE, HAVE_USHORT_TYPEDEF, HAVE_ULONG_TYPEDEF, HAVE_U16_TYPEDEF, and HAVE_TYPE_U32. * configure.ac (byte, ushort, ulong, u16, u32): Use AC_CHECK_TYPES.
- Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>