R1:467308dd12e2

Script to selectively convert MyISAM tables to InnoDB

Summary:
A bunch of the .sql patch files don't explicitly specify the table engine, but
we should always use InnoDB with the exception of one table which needs MyISAM
for FULLTEXT.

MySQL doesn't no-op an ALTER TABLE statment that changes the engine back to
itself and converting large tables can be time consuming, so convert only the
required tables.

Test Plan: Ran on secure.phabricator.com and my local box, it fixed all the
issues in about 3 seconds…