o use predefined macros to test for sys/wait.h, time.h and sys/time.h
o search strcasecmp in libresolv only if strcasecmp and stricmp are not in libc
o use predefined macro AC_SYS_LARGEFILE to determine 64Bit I/O
o determine the alignment of long and double (ALIGNMENT,DOUBLE_ALIGN),
still need to write a test for FB_ALIGN!
o autoconf v2.53 and later is now required to generate configure
(sorry, but it makes many tasks easier)
o improved tests for mmap, socklen_t and offt_64
o added tests for atexit, on_exit, (v)fork, set(p)grp, setpgid and flock
o added test for the keyword 'volatile'
o fixed errors in configure.in
o updated config.h.in and autoconfig_msvc.h (the latter may be incorrect)
o replaced VOLATILE by volatile
o removed SETPGRP and ATEXIT
o replaced NO_FLOCK by HAVE_FLOCK
o SIG_FPTR cleanup
o vfork cleanup
