...and for PURGE BEFORE too. (Don't fix_fields in the parser!)


mysql-test/r/sp-error.result:
  New test case for BUG#6807
mysql-test/t/sp-error.test:
  New test case for BUG#6807
sql/sql_lex.h:
  Purge and kill query args not needed in lex. (Using value_list instead)
sql/sql_parse.cc:
  Evaluate purge before and kill query args in mysql_execute_command
  instead of in the parser. (Makes it work with stored procedures)
sql/sql_yacc.yy:
  Don't evaluate (fix_fields) args in the parser for purge before and kill query.
  (Doesn't work with stored procedures)