YA readline 4.2 patch

The attached patch enables PostgreSQL CVS to build cleanly under Cygwin
when built against readline 4.2. Specifically, it handles the deprecation
of

filename_completion_function()

with preference for

rl_filename_completion_function()

Although, I was motivated by Cygwin support, IMO this patch is appropriate
for all platforms. To quote from the readline source:

#if 0
/* Backwards compatibility (compat.c). These will go away sometime. */
...
extern READLINE_EXPORT(char, *filename_completion_function) ...
#endif

Note that this patch is modeled after the one by Peter Eisentraut for
completion_matches():

http://www.ca.postgresql.org/~petere/readline42.html

I tested this patch under the following environments:

Cygwin with readline 4.1
Cygwin with readline 4.2
Linux with readline 2.2.1
Linux with readline 4.2

and it behaved as expected.

Thanks,
Jason

--
Jason Tishler
Director, Software Engineering Phone: 732.264.8770 x235
Dot Hill Systems Corp. Fax: 732.264.8798
82 Bethany Road, Suite 7 Email: Jason(dot)Tishler(at)dothill(dot)com
Hazlet, NJ 07730 USA WWW: http://www.dothill.com