Re: Add A Glossary

I did some of the grunt work Alvaro alluded to in v6, and the results are attached and they build, which means there are no invalid links.

Notes:

* no definition wordings were changed

* added a linkend to all remaining glossterms that do not immediately follow a glossentry

* renamed id glossary-temporary-tables to glossary-temporary-table
* temporarily re-added an id for glossary-row as we have many references to that. unsure if we should use the term Tuple in all those places or say Row while linking to glossary-tuple, or something else
* temporarily re-added an id for glossary-segment, glossary-wal-segment, glossary-analytic-function, as those were also referenced and will need similar decisions made
* added a stub entry for glossary-unique-index, unsure if it should have a definition on it's own, or we split it into unique and index.

* I noticed several cases where a glossterm is used twice in a definition, but didn't de-term them

* I'm curious about how we should tag a term when using it in its own definition. same as anywhere else?