Re: Flexible configuration for full-text search

The following review has been posted through the commitfest application:
make installcheck-world: tested, passed
Implements feature: tested, passed
Spec compliant: tested, passed
Documentation: tested, passed

This patch seems to be in a pretty good shape. There is a room for improvement
though.

1. There are no comments for some procedures, their arguments and return
values. Ditto regarding structures and their fields.

2. Please, fix the year in the copyright messages from 2017 to 2018.

3. Somehow I doubt that current amount of tests covers most of the
functionality. Are you sure that if we run lcov, it will not show that most of
the new code is never executed during make installcheck-world?

4. I'm a bit concerned regarding change of the catalog in the
src/include/catalog/indexing.h file. Are you sure it will not break if I
migrate from PostgreSQL 10 to PostgreSQL 11?

5. There are typos, e.g "Last result retued...", "...thesaurus pharse
processing...".

I'm going to run a few more test a bit later. I'll let you know if I'll find
anything.

The new status of this patch is: Waiting on Author