pspell configuration requirements hosed

[Geoffrey Leach <geoff cdepot net>]

The environment is RH 9 with aspell-0.50 locally compiled and pspell/
pspell-devel 0.12.2-16 installed from the distribution.

configure does not know about the need to have pspell -- HAVE_LIBPSPELL 
is not defined.

However, building balsa, undefined reference to `pspell_config_replace'
spell-check.o(.text+0x13e9):/usr/local/src/ftp/balsa-2.0.11/src/spell-
check.c:800

One reference to this function can be found in balsa_spell_check_start
() and is not that I can discover guarded in any way.

-lpspell does not appear in the constructed Makefile.  Adding it 
resolves the problem.

So, perhaps the configuration wizard can update the requirements?