Zope3-dev Collector #139: Memory leak involving buckets and connections

Connection objects were typically immortal because the threaded
transaction manager kept them in ever-growing lists.  Reworked the
transaction manager internals to use a simple implementation of weak sets
instead.  This plugs all leaks in the test program attached to the
collector report (which was leaking about 100KB/sec on my box).

Forward-porting from Zope 2.7.
Merged from 3.3 branch, revision 26085.

The checkFullTimeStamp() test was sensitive to unique mktime() behavior
on FreeBSD.  See:

http://lists.freebsd.org/pipermail/freebsd-standards/2003-November/000268.html 

The purpose of this test is to exercise ZODB's TimeStamp object, so got
rid of dependence on platform mktime() and time.timezone quirks --
TimeStamp works in GMT, so how mktime() treats tm_isdst should be
irrelevant in all TimeStamp tests.

Also added a comment about the highly non-obvious numeric characteristics
of TimeStamp's treatment of seconds (round-tripping is surprisingly
inaccurate, but for a real reason).

New interface IResourceManager intends to combine the
best aspects of IDataManager and IDataManagerOriginal,
and will become "the" interface.
New interface ISavePoint captures (along with models in
collaborations.txt) what should be a clean design for a
savepoint/rollback facility that actually works.

Updated an old collaboration to reflect the change.

are in now (partly ZODB 3, partly ZODB 4, partly transitional).
More is needed.
Added new collaborations.txt, which spells out some dynamics
of the system in a compact way.  This is in a format Jim used
for Zope 3, essentially a flat-text and less-formal representation
of UML sequence diagrams.

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and include that in the ZODB project.  While we're at it,
include zope.testing too, as zope.interface depends on that,
and we had copied zope.testing.loggingsupport.py into ZODB
earlier anyway (and delete that unique copy here now).

This also merges some changes made to the ZODB copy in
Zope3 back into ZODB.

Collector 1327:  FileStorage init confused by time travel

If the system clock moved back in time more than 30 days between
a FileStorage close and (re)open, new txn ids could be smaller
than txn ids already in the database.  Plugged that hole.

3.3 didn't have the bug, and this confirms it.

(identical to revision 25416 on the ZODB-3.3 branch, but svn would not merge
the change)

(equivalent to revision 25293 on the ZODB 3.3 branch, but not a merge, since
the files were added separately after the branch was made)

this was in Releases/ZODB3/ on cvs.zope.org

worker thread creates could cause mysterious exceptions in
*later* tests (when running all the tests, they appeared
to come out of checkDetail, which runs right after
checkMinimizeTerminates).  Changed the CantRidOfMe class
so that instances of the class *can* be gotten rid of,
keying off a new module bool.  The checkMinimizeTerminates
worker thread uses this to defang the objects after the
body of the test has completed.

In replace(), print feedback to stderr, since fileinput
hijacks stdout.

release, tried to make this script much more robust.  Use
r-strings for regexps.  Junk unnecessary code that a Unixhead
probably thought was needed for Windows (replacing forward
slashes in filepaths -- Windows accepts those too).  Made
the search criteria for NEWS.txt much looser (this is the
one we seem to blow most often).  Changed replace() in
several ways:  only replace the first occurrence of the
pattern (we never need more than that, and looser searches
are dangerous when replacing all occurrences); provide
feedback on everything done; if the pattern isn't found
at all, print a noisy msg saying so.  Completed the list
of modified files in the module docstring.

SAX stuff (that all comes with the minimum Python needed
to run ZODB now).

God knows it will get out of synch someday, but continuing to call
it version 0.3a2 is crazy.

Call it beta 1.  Recommend Python 2.3.4.  Retract the promise that ZEO incompatibilities will be fixed in
beta 1.

to the dead StandaloneZODB project at SourceForge.

cacheMeanDeal, and cacheMeanDeac methods from the DB class.  They
were untested, undocumented, unused, and did nothing of use (the
first always returned an empty tuple, the rest always returned None).