MySQL backend fixes for Python 3. With Python 2, text sent to and from MySQL is treated as bytes in Python. The database may be recorded by MySQL as having some other encoding (latin1 being the default in some MySQL versions - Roundup does not set an encoding explicitly, unlike in back_postgresql), but as long as MySQL's notion of the connection encoding agrees with its notion of the database encoding, no conversions actually take place and the bytes are stored and returned as-is. With Python 3, text sent to and from MySQL is treated as Python Unicode strings. When the database and connection encoding is latin1, that means the bytes stored in the database under Python 2 are interpreted as latin1 and converted from that to Unicode, producing incorrect results for any non-ASCII characters; furthermore, if trying to store new non-ASCII data in the database under Python 3, any non-latin1 characters produce errors. This patch arranges for both the connection and database character sets to be UTF-8 when using Python 3, and documents a need to export and import the database when moving from Python 2 to Python 3 with this backend.

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 run_tests.py

   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.