Diffs broken after upgrade to Comment Alter 1.0-rc4

There was a minor API change in Comment Alter 1.0-rc4 that I totally forgot about! The return value for comment_alter_get_changed_fields() went from an array of associative arrays to an array of an array of associative arrays.

This means that the diff of everything except files is broken and the field names don't get shown.

I'll fix it in a moment!