Fixed bug in MAX() optimizing for BDB tables

Docs/manual.texi:
  Updated changelog
mysql-test/README:
  Added reference to manual
mysql-test/r/bdb.result:
  Added test for MAX() bug
mysql-test/r/innobase.result:
  Added test for MAX() bug
mysql-test/t/bdb.test:
  Added test for MAX() bug
mysql-test/t/innobase.test:
  Added test for MAX() bug
sql-bench/server-cfg.sh:
  Don't create big blobs with innobase
sql/ha_berkeley.cc:
  Fixed bug in MAX() optimizing
BitKeeper/etc/ignore:
  Added sql/.gdbinit to the ignore list
sql/ha_innobase.h:
  Fixed bug in MAX() optimizing
sql/handler.h:
  Fixed bug in MAX() optimizing
sql/opt_sum.cc:
  Fixed bug in MAX() optimizing