Summary: Add test cases for sqlite fts Add support for using the FTS5 full text query engine for sqlite. Also stubbed out some sections for adding postgresql FTS support as well. Added nee indexer type native-fts. It is not selected by default. The indexer=native is used if no indexer is set. This prevents an upgrade from seeming to wipe out the native index if upgraded and indexer=native is not explicitly set. Docs updated. Also changed section headers to sentence case for the current release notes. Indexing backend can control if the full text search phrase is broken into a list of words or passed intact. For backends with query languages (sqlite and can be enabled for whoosh and xapian) we do not want the phrase "tokenized" on whitespace. This also updates the rdbms database version to version 7 to add FTS table. I will be using the same version when I add postgresql. If somebody runs this version on postgresql, they will have to manually add the fts tables for postgresql if they want to use it. Added a new renderError method to client. This allows errors to be reported still using page.html rather than raw html. It also supports templates for any error code. If no template for the error code (e.g. 400) is found, the error in raw html with no page frame is shown. New IndexerQueryError exception to pass back message about query syntax errors.

Debugging Aids
--------------

Try turning on logging of DEBUG level messages. This may be done a number
of ways, depending on what it is you're testing:

1. If you're testing the database unit tests, then set the environment
   variable ``LOGGING_LEVEL=DEBUG``. This may be done like so:

    LOGGING_LEVEL=DEBUG python -m pytest test/

   This variable replaces the older HYPERDBDEBUG environment var.

2. If you're testing a particular tracker, then set the logging level in
   your tracker's ``config.ini``.

SENDMAILDEBUG
=============

Set to a filename and roundup will write each email message
that it sends to that file instead to the internet. 
This environment variable is independent of the python -O flag.