Fix doctest example.
Mention in the tutorial that 'errcheck' is explained in the ref manual.
Use better wording in some places.
Remoce code examples that shouldn't be in the tutorial.
Remove some XXX notices.

is that the wait is failing for some reason.  Use WNOHANG, so we won't
wait until the buildbot kills the test suite.

I haven't been able to reproduce the failure, so I'm not sure if
this will help or not.  Hopefully, this change will cause the test
to fail, rather than hang.  That will be better since we will get
the rest of the test results.  It may also help us debug the real problem.

issues that crop up from time to time, but this change seems to have been
pretty stable (no spurious warnings) for about a week.

Other modules which use threads may require similar use of
threading_setup/threading_cleanup from test_support.

Old url returned status code:301 Moved permanently.

Tkinter variable classes.

(implementation/tests contributed by Sam Ruby)

of this test.  It probably still requires more disk space
than most buildbots have, and in any case is still so
intrusive that if we don't find another way to test this I'm
taking my buildbot offline permanently ;-)

This will hopefully get the buildbots to pass.  Not sure this
test will be feasible or even work.  But everything is red now,
so it can't get much worse.

  now works reliably.  It has been updated to use automatic BerkeleyDB
  deadlock detection and the bsddb.dbutils.DeadlockWrap wrapper to retry
  database calls that would previously deadlock. [SF python bug #775414]

until Gerhard has time to fully debug the issue.  This affects versions
before 3.2.1 (possibly only versions earlier than 3.1.3).

Based on discussion on python-checkins.

This backs out the test changes in 46962 which prevented crashes
by not running the tests via a version check.  All the version checks
added in that rev were removed from the tests.

Code was added to the error handler in connection.c that seems
to work with older versions of sqlite including 3.1.3.

  SQLite versions.
- Added version checks in test suite so that we don't execute tests that we
  know will fail with older (buggy) SQLite versions.

Now, all tests should run against all SQLite versions from 3.0.8 until 3.3.6
(latest one now). The sqlite3 module can be built against all these SQLite
versions and the sqlite3 module does its best to not trigger bugs in SQLite,
but using SQLite 3.3.3 or later is recommended.