Products-zctextindex

------------------

------------------

- Mark as compatible with Python 2 and 3.

------------------

- Fix version number of ZCatalog requirement to be PEP compliant.

----------------

- Move code into ZCatalog distribution.

- Implement new `IQueryIndex` interface.

- Require at least Zope and ZCatalog 4.0.

----------------

- Replace stopper and okascore C implementations with pure-Python.

- Remove HelpSys pages.

- Remove various internal test helper modules.

- Remove old-style interface modules, use the interfaces module instead.

- Update to ZODB 4.x as direct dependency. Which drops ZODB3 support.

-------------------

- Add `getIndexQueryNames` method to index to comply with extended interface.