src/configure.in broken since 1.56

[Wolfgang J. <wje...@in...>]

Apparently, some autoconf macro invocations which were removed in
src/configure.in 1.56 are still needed.  Here are the tests which
unexpectedly fail (on Linux 2.4.19 i686, libc-2.3.1, gcc 3.3) together
with what I think are the reasons.

checking for usable closedir return value
         OPENDIR_CONST is not defined anymore; previously it was
         defined via CL_OPENDIR (opendir.m4 was removed)

checking for the malloc address range
         RETMALLOCTYPE and MALLOC_SIZE_T are not defined anymore;
         previously defined via CL_MALLOC (still there but called
         only at some later point in some other configure.in)

checking for working mprotect
         same as above

checking for working shared memory
         cl_cv_proto_shmget_arg2 etc. are not set anymore.
         Previously this was done via CL_SHMGET, CL_SHMAT, CL_SHMDT
         and CL_SHMCTL.

checking for the valid characters in filenames
         CHDIR_CONST and OPENDIR_CONST are not defined anymore;
         previously CHDIR_CONST was defined via CL_CHDIR (chdir.m4 was
         removed)                 

Wolfgang