Comment 7 for bug 815717

- It is called when building the sampledata to set all the fti columns to NULL
- It is also called after populating our databases with sampledata to revert this, changing all the NULLs to real data. This shrinks the size of our sample data scripts, and makes things more robust with regards to manual edits of the sample data file.
- It is called to install tsearch2 into empty databases, before installing the 'baseline' schema dump. This also includes the helpers we have written, such as ftq().

I'm advocating leaving things as they are until we know how we are going to be maintaining changes to production. At the moment, to change full text indexes on production we would either roll a custom script to apply (probably as a database patch to run as part of a fastdowntime deploy), or we would integrate fti.py into the fastdowntime deployment script somehow (perhaps modifying it to generate .sql that is then included in the big script executed by update.py and avoiding the overheads that caused us to remove it from fastdowntime deployments earlier).