1. PHP_CHECK_FUNC(func, lib1, lib2, ..., libn) searches for

1. PHP_CHECK_FUNC(func, lib1, lib2, ..., libn) searches for
   func and __func using LIBS, and if unsuccessful, searches
   each specified lib.  Defines HAVE_FUNC, if found.  If func/__func is
   found in library foo, HAVE_LIBFOO is defined.

   (Jani, me)

2. Autoconf 2.5x is more pedantic regarding locating header files.
   We include the proper header files now in the check. (me)

3. The nsl/bind/socket/etc checks have been rewritten using PHP_CHECK_FUNC.
   This ensures that no extra library is used, if the symbol is
   available in libc which avoids issues on BSD/OS, OpenBSD and others.
   (Jani)