WL #2604: Partition Management

Optimised version of ADD/DROP/REORGANIZE partitions for
non-NDB storage engines.
New syntax to handle REBUILD/OPTIMIZE/ANALYZE/CHECK/REPAIR partitions
Quite a few bug fixes

storage/example/ha_example.cc

@@ -103,6 +103,8 @@ handlerton example_hton= {
   NULL,    /* Start Consistent Snapshot */
   NULL,    /* Flush logs */
   NULL,    /* Show status */
+  NULL,    /* Partition flags */
+  NULL,    /* Alter table flags */
   NULL,    /* Alter tablespace */
   HTON_CAN_RECREATE
 };