Do not test for sys.exc_info(); it was already present in Python 2.1.
This simplifies code and improves performance (very slightly).

In two places, object type was tested by calling type() on each of two
values and comparing the results (4 dict lookups, 2 Python->C function
calls).  Replace each with an isinstance() call comparing to a saved
type object (3 dict lookups, 1 Python->C function call, more future-proof).

Moved ISO8601 into DateTime class.
DateTime constructor now also accepts ISO8601 dates.

Fixed (hopefully) a longtime outstanding problem in parens():
- the former regex never matched any parentheses
- the parens() used old regex module API although 're' module was used

- the former regex never matched any parentheses
- the parens() used old regex module API although 're' module was used

:img:

REQUEST object recently got a method named "text" that interfered with
the form elements name).

Only pick up mloads & mdumps from one location; since the "real" source is
marshal, we'll keep that one.

Added 'users_with_local_role' method.  This method takes a role string (e.g. 'Owner') as an argument and returns the usernames which have that local role respective to the object which is asked.  The username is returned as a bare string (without a database path).

Fix imports so that XML import works with Python 2.1.  The addition of
__all__ to the pickle module, and the import constraints that causes symbols
not listed in __all__ not to be imported by "import *", caused these modules
to break because some names were not acquired from the pickle module which
had been acquired before.

This patch adds the appropriate imports so that dependence on the pickle
module's implementation details is avoided.

PluginIndexes as first product in any case. (Collector #2273)

- made parseIndexRequest much more smarter in parsing the request parameter

Note that requirement of Zope 2.2 or higher.  Explain how to put
cPickle in the right place in your Zope tree.

This ensures the interfaces are returned as a list and isolates knowledge of
the "__implements__" attribute.