mysql-test/r/partition.result:
  Added test case
mysql-test/t/partition.test:
  Added test case
sql/sql_partition.cc:
  Do mysql_trans_prepare_alter_copy_data() after all original tables are locked.
  (We don't want to disable transactions for the original tables, that still may be in the cache)
sql/sql_table.cc:
  Fixed two wrong DBUG_ENTER