"This time for sure!"

missing out on __traceback_supplement__.

Fixes issue with AcceleratedHTTPCacheManager sending PURGE from a
virtual-hosted zope, and adds a bunch of related tests and comments.

Collector #2072: Applied patch to fix problem with overly restrictive __bobo_traverse__ security and tests.

(Fix for collector #1770 that never made it.)

and the related addition of an environ argument to
Testing.makerequest.  This was not a bugfix, thus inappropriate
for the stable branch.  Apologies.

this caused failures in testVirtualHostMonster when Testing/makerequest
was modified. 

it now wraps Testing.makerequest.makerequest().

when used on anything other than an app object.
Also added an 'environ' argument if you want to use something
other than os.environ, and added a couple trivial tweaks from 
ZopeTestCase.makereqeust.
Added unit tests for this stuff.