Revert "Give up on my naive dream of parallelizing this"

This reverts commit 531f4df805a0bd6f04c4f275f7322e5b091d626b.

With the innodb_file_per_table=OFF option, you can now do parallel MySQL stuff
on Mac.

http://stackoverflow.com/questions/17813630/mysql-5-6-headaches-on-mac-osx