fix for a bug with derived tables and query cache
ix for a charset bug in timestamp


mysql-test/r/multi_update.result:
  aliases with multi-table updates / deletes
mysql-test/r/query_cache.result:
  fix for query cache with derived tables
mysql-test/t/multi_update.test:
  aliases with multi-table updates / deletes
mysql-test/t/outfile.test:
  Fix of bug with charset in timestamp
mysql-test/t/query_cache.test:
  fix for a bug with derived tables and query cache
sql/field.cc:
  fix for a charset bug in timestamp
sql/sql_parse.cc:
  aliases with multi-table updates / deletes
sql/sql_yacc.yy:
  aliases with multi-table updates / deletes