Sync glossary and firstterm

Ensure that for each firstterm, we have a proper entry in the glossary:
* Use <firstterm baseform="xxx"> if the first term is spelled differently
  than the glossary entry.
* Remove some firstterm markups where no entry is in the glossary
  and adding one not useful.

Change-Id: Id7093a53f9d466db774b548749116288425af581
Merge "Sync glossary and firstterm"