Portability is a big issue for this document.

Makefile needs an 'include' statement to pull in 'config.mak'.
This works successfully with GNU and SunOS.

config.sh does not require bash, but a lot of other scripts
probably still do.

We need a POSIX compliant sed with character classes.

Debian 2.2r6 ships with Perl 5.0 patch level 5 subversion 3.
This version does not support:
+ use constant
+ [:xdigit:]
+ open() with three arguments

On FreeBSD/alpha the ELF base address is a 64-bit address above 4GB.
At least one such machine runs a Perl with 32-bit integer arithmetic.
'./configure' avoids the issue by treating ELF_BASE as string, not a number.
'etc/calc.pl' could use 'bc' for calculations. The alternative is writing
a BCD module. FIXME.

Hexadecimal shell variables are output without leading '0x' to enable
echo "ibase=16; ${ELF_BASE} + 1" | bc
The corresponding defines for C code (in config.h) are complete with 0x.
BTW: None of the defines are quoted. I have clean way to distinguish
TEVWH_ELF_EHDR (will never be quoted) and TEVWH_OS_NAME.

Option '-r' is an extension of GNU xargs. FreeBSD does not have it.
On Solaris 2.6 /bin/find has no -print0 and bin /bin/xargs has no '-0'.
file 3.27 on Debian 2.2r6 has no -i.

Options '-A' and '-B' are extensions of GNU grep. Solaris 2.7 does not
have them.

The tool test, also known as [ ], does not have -e on Solaris.
