ZEO4 is considered "dead" by upstream:

	https://github.com/zopefoundation/ZEO/pull/161#pullrequestreview-447245642

Keep on patching ZEO4 in our local fork until ZEO4 is used.

Mainly to have a backup cache for new branches (although this won't
help that much because of the differences between ZEO4 and ZEO5,
still...

Also stop testing on mac. I do that enough already. :)

Also, use a simpler leaner install script.

Convert cache_stats and cache_simul from getopt to argparse.

Fix tracing of loadBefore with empty tids on Py3.

Update zeo-client-cache-tracing to use accurate script names.

I haven't actually compared the output snippets (yet), but at least the
script references are right now.

Fix connecting to 'localhost' on Windows / Solaris / Android.

Closes #8.

Closes #30.

Close opened-file leak in blob cache size check.

Closes #27.

Changed tests to not depend on ZODB underware

Zodb5

This is required (or maybe strongly implied) by the IStorage interface.

Also, rearrange the order of operations in _process_invalidations.

Each of these changes avoid a potential race when a connection starts
a transaction while invalidateTransaction is being called. Basically,
we don't want a connection to get a lastTransaction corresponding to
invalidations it hasn't processed.

This neither fixes nor provokes any test failures. :) The need for
this change was discovered via code inspection. It's hard to see how
to test the race without getting being insanely whitebox.

To avoid an error on tearDown.

Fix #22

Adding osx back.

Also adding back -j99, in hopes of getting quicker runs and making
travis nor hate us so much.  But then, we'll probably get more
failures. Maybe the best option will be to just make test pass even
when starved. :(

traviiiiiiiiis

A test was counting on a cache being written to, but it wasn't because
the storage got an invalidation later than expected (on suitably slow
machines, like travis and an AWS dev machine of mine).

that was making a test failure hard to interpret.