- AccessControl.User used a misleading string exeception,
       'NotImplemented', which shadowed the Python builtin.

Removed support for Python 2.1, fixed yield test, and added a test for
bad names set by exception handlers.

the list of names

Added tests.

throwing OverflowError.

that depends on it to raise an OverflowError when presented with a
number above sys.maxint.  We work around it here.

preferred spelling for 'CONTEXTS/varname'.

to REQUEST.URL to prevent accidental overriding.

notice that the date is a long.

Make the cache manager report correct values for the object cache size.

_delObject. This could break code expecting to do cleanups before
deletion.