Get rid of the last two MyISAM tables

I'm running this as a pull request to make sure someone looks at this before we merge it.

Since InnoDB fulltext indexes were only recently added to MySQL 5.6 we can't use them quite yet. What I did for now is simply remove the fulltext index. From what I could see in my limited testing, ca_media_content_locations.content usually has one or two words in it. We might just want to convert it to a shorter field (it's longtext now) and live with the normal index we have. We don't do any complicated MATCH (...) AGAINST queries with this, just simple LIKE queries without wildcards. So I think we're fine without the fulltext index.

Also, there was a 'page' field in the table that had no default and wasn't listed in the field list of the INSERT query in MediaContentLocationIndexer, causing MySQL errors (no default value). Since it's not used, I just dropped it.