only MyISAM is fixed


include/m_ctype.h:
  my_charpos() macro
myisam/mi_key.c:
  apply UNIQUE constrain correctly for multi-byte charsets
mysql-test/r/binary.result:
  new test
mysql-test/r/key.result:
  apply UNIQUE constrain correctly for multi-byte charsets
mysql-test/t/binary.test:
  new test
mysql-test/t/func_gconcat.test:
  make test to pass w/o InnoDB
mysql-test/t/key.test:
  apply UNIQUE constrain correctly for multi-byte charsets