Not fixed in 4.1 as not critical. Also I'm correcting error checking of multi-UPDATE/DELETE
when it comes to binlogging, to make it consistent with when we rollback the statement.
Cleaned up embedded library access and query cache handling
Changed min stack size to 128K (to allow longer MyISAM keys)
Fixed wrong priority for XOR (should be less than NEG to get -1^1 to work)
we change THD::system_thread from a 'bool' to a bitmap to be able to
distinguish between delayed-insert threads and slave threads.
- Fix for BUG#1701 "Update from multiple tables" (one line in sql_parse.cc,
plus a new test rpl_multi_update.test). That's just adding an initialization.