Log Message:
Changes 4.0.2:
1. Infrastructure upgrades: Autoconf 2.69, Automake 1.12.6, bison 2.7.
2. `fflush()', `nextfile', and `delete array' are all now part of POSIX.
3. fflush() behavior changed to match BWK awk and for POSIX - now both
   fflush() and fflush("") flush all open output redirections.
4. Various minor bug fixes and documentation updates.