Additional storage engine called "blackhole". Customer request, and for that matter a Zawodny request.  With this you can alter table to a type of table that would never store data. Its a /dev/null for a database.  


acinclude.m4:
  New macro rule for ha_blackhole.
configure.in:
  Rule enabling blackhole engine
sql/Makefile.am:
  Additions to Makefile for blackhole engine
sql/handler.cc:
  Ifdef enable code for blackhole (and message for "what does this thing do").
sql/handler.h:
  Flag for storage engine type.
sql/mysql_priv.h:
  Added blackhole type.
sql/mysqld.cc:
  Updates for building backhole.
sql/set_var.cc:
  Show variable for blackhole engine