sql/item_sum.cc:
  Add in bit_xor class functions.
sql/item_sum.h:
  Add bit_xor class.
sql/lex.h:
  Add in bit_xor symbol.
sql/sql_yacc.yy:
  Add in bit_xor function
BitKeeper/etc/logging_ok:
  Logging to logging@openlogging.org accepted