The picklelog branch attempts to improve performance and reduce the
possibility of lock file exhaustion by optimistically writing pickle
and metadata tables at the store() call instead of during the
_finish() call.  store() will be bounded in the number of objects it
touches, but _finish() is unbounded, so we try to reduce the number of
database pages the latter might actually touch.

Other performance improvements are implemented based on hotshot
profiling.  The use of an extension module for Python 2.2 also speeds
up a critical loop.

This also implements the periodic checkpointing to improve recovery
times when the database is not cleanly shutdown.

doing a critical operation in C.  When fiddling the reference counting
we often need to

    1. unpack a 64bit string into a long
    2. add a delta value to the long
    3. pack the long into a 64bit string

_helper.incr() does these three steps in C.

This extension only works for Python 2.2, but Full.py has a Python
replacement for use with Python 2.1.

write_object(): uses the `x' opcode, which is very similar to `o'
except that the metadata is written optimistically during store() so
it shouldn't be written during _finish().

- Added BerkeleyConfig class for easier configuration of checkpointing
  policy and lock sizing.

- Added _lockstats() and _docheckpoint() helpermethods.

Checking why the tests are failing, i discovered a typo on the test. But unfortunately the tests are still failing. :(

returnf() function will definitely get called.  Otherwise, if we get
an exception during the test, we'll deadlock because it's returnf()
that releases the various test locks.

loadinc(): Pass the file pointer in as well as the mbox so that the
status printing will actually work.  I'm not passing the file in
/instead/ of the mbox, but I wasn't completely sure of the original
intent of the code.

Disabled tests that's probably broken during investigation.

If self->meth is something other than a PyFunction,
for example an ExtensionClass Method object, the blind cast breaks.  The
new code uses the string "(?)" if self->meth is not a function.

byte ranges because Acrobat Reader for Windows chokes when overlapping
ranges have been merged.

bug.  Before the fix, ZopeSecurityPolicy saw the aq_base global and thought
the module object was wrapped, leading to unexpected behavior.

in the error value.  It may provide extra info.

are not normally attributes of any object but acquisition wrappers, except in
one important case: if container is a module and that module happens to
import aq_base or aq_acquire from Acquisition, ZopeSecurityPolicy.validate()
does unintended things.  This made ModuleSecurityInfo declarations fail when
using the Python policy.

Now we no longer look at aq_base attributes, but rather the acquisition API,
which is what cAccessControl does.

- Show the most recent log entry first.

and lack of coverage in the code.

- Documented FORCE_PRODUCT_LOAD

- Changed FORCE_PRODUCT_LOAD so that if it is set, it determines
  whether products are installed regardless of whether ZEO_CACHE is
  set. This means that you can disable product installation by setting
  FORCE_PRODUCT_LOAD to an empty string even if you are not using a
  ZEO persistent cache.

- Fixed the help system and Zope Tutorial product to honor
  FORCE_PRODUCT_LOAD.

testrunner output.

When a set of knobs is set on the browser_id_manager "settings" screen,
("look for browser id name in..." and 'automatically encode browser ids..."),
a traversal hook is installed in the browser id manager's container which
causes a) the request to be searched for a browser id name and a browser
id as the first two elements of the URL path and b) for Zope-generated URLs
to contain these path elements.

Various documentation and interface updates.  No interface methods
were harmed in the filming of this checkin, but a few were added or extended
with defaults.

Fix for collector #510, When Python scripts and other "Script" objects were acquired during URL traversal, the __before_publishing_traverse__ code did not properly stop traversal at the script and populate traverse_subpath with the remaining url path elements.

depending on whether the full or a partial test suite was run.  In
particular, in my case there was a EVENT_LOG_FILE turd left in the
environment which was causes StupidLogTest's checkBasics to fail.

The fix is to wipe the environment in both the setup and the tear
down, although I wonder why EventLogTest's teardown didn't clean
things up properly.  Hmm, with this patch the test suite succeeds.

use that everywhere internally instead of setting the global _log_dest
directly.