* config/srclist.txt: Temporarily comment out mktime.c until glibc bug

* config/srclist.txt: Temporarily comment out mktime.c until glibc bug
2821 is fixed.

* lib/mktime.c (guess_time_tm): Fix bug where mktime
returned the maximum time_t value rather than (time_t) -1.
Problem originally reported by William Bardwell
<http://sourceware.org/bugzilla/show_bug.cgi?id=2821>.

* m4/mktime.m4 (AC_FUNC_MKTIME): Sync from Autoconf.
Check for unistd.h too, since Autoconf doesn't assume POSIX.
Also:

2006-09-08  Paul Eggert  <eggert@cs.ucla.edu>
Add year_2050_test to catch glibc bug 2821
<http://sourceware.org/bugzilla/show_bug.cgi?id=2821>.

2006-08-15  Paul Eggert  <eggert@cs.ucla.edu>
Prefer #ifdef to #if.

2006-04-02  Paul Eggert  <eggert@cs.ucla.edu>
Return from 'main' instead of calling 'exit'.