Tablespace support per partition was not included
when wl#6035 (InnoDB native partitioning)
and wl#6205 (InnoDB support for general shared tablespaces)
was added.

This enables support for general shared tablespaces also for
partitioned innodb tables.

Also fixed the output of SHOW CREATE TABLE to quote
the tablespace name as an identifier.

Also fixes test for bug#20588947.