* instead of including <sys/cdefs.h> (not in Solaris), we hope <sys/types.h>
  includes it for us
* autoconf-test for <sys/param.h> (not in SUSv3) existence
optic sugar
fix another warning

now builds on MirOS, DragonFly, NetBSD, Debian stale (i386), Solaris 8,
Debian testing (s390x) - Solaris /bin/sh, bash, ksh93, mksh
add the new function utf_ptradj() which does the same as utf_widthadj()
except it doesn't return a value and is much cheaper (no internal con-
version to UCS-2, just range checking on the multibytes)
optimise and, ahem… plug…
fix SIGSEGV, we are passed NULL sometimes
get rid of the need of strlcat() altogether (only one use was left)
missed these
using a function instead of a macro saves 896 bytes of .text
optional (#ifdef MKSH_SMALL) saving of 364 more bytes of .text
intended e.g. for FreeWRT
make a few functions static that should be, and optimise a little
simplify getconf and confstr stuff
more getconf/confstr fixes
don't compile mknod(1) builtin if MKSH_SMALL
saves 1037 text, 20 data (on i386)
save 464 text with restructuring
ac_test for MKSH_SMALL presence in CPPFLAGS
if present, don't even look for setmode as it's only used by mknod builtin
unbreak -d (was broken in R28)
new function ac_testn() does the same as ac_test() but doesn't amend CPPFLAGS
simplify
check for a few more things