Removed not needed table renames when doing ALTER TABLE when engine
changes and both of the following is true:
- Either new or old engine does not store the table in files
- Neither old or new engine uses files from another engine
We also skip renames when ALTER TABLE does an explicit rename
This improves performance, especially for engines where rename is
a slow operation (like the upcoming S3 engine)
Replace ha_notify_table_changed() with notify_tabledef_changed()
Reason for the change was that ha_notify_table_changed() was done
after table open when .frm had been replaced, which caused failure
in engines that checks on open if .frm matches the engines table
definition.
Other changes:
- Remove not needed open/close call at end of inline alter table.
Some test that depended on the table beeing in the table cache after
ALTER TABLE had to be updated.