Rewrote if-statement a bit shorter
Added check for subpartitions in REORGANIZE partitions to be of same number as
in base table.


mysql-test/r/partition_mgm.result:
  New test case
mysql-test/t/partition_mgm.test:
  New test case
sql/ha_partition.cc:
  Fixed stuff I should done long ago (monty comments)
sql/sql_partition.cc:
  Rewrote if-statement a bit shorter
  Added check for subpartitions in REORGANIZE partitions to be of same number as
  in base table.