(AC_DEFINE_NOAUTOHEADER): New - work around bug in autoheader.
* configure.in: Call AC_C_INLINE and AC_C_CONST. Use three
argument form of AC_DEFINE in dummy definitions block. Use
AC_DEFINE_NOAUTOHEADER for real definitions of things defined
in dummy block. Preload cache variables instead of bypassing
tests, where possible.
* acconfig.h: Removed.
* xmalloc.c (xmalloc_failed): New function, does error
reporting on failed allocation.
(xmalloc, xcalloc, xrealloc): Use it.
