Removed Tabulator.php

- Also removed tables/Multitable{,Transposed}.php
- These where for rendering the templates in PHP,
  but as they are no longer necessary, they've now been removed.
Added valueManager.deps

- I use this file to track which parts of the page still depend on the ValueManager.
  The ValueManager used to be the core of the site, supported by the database classes.
  This is no longer the case, since most work is now performed client side,
  and the database contents are delivered to the client via query/Dataprovider.php.
- I'll try to reduce these dependencies to remove the old code step by step.
Bugfix in StudyTitleTranslationProvider
Bugfix in updateDescription routine in translation

- When trying to update some descriptions, the update failed silently.
  This should no longer be the case, because we're now using a
  combination of DELETE/INSERT queries rather than a single UPDATE or
  an INSERT with 'ON DUPLICATE' clause.