Dont try to set attributes on cfg in setConfiguration if we're trying to clear the configuration by passing it None.

- only sort the results once

Added getId() to Item_w__name__, since the one inherited from Item
has broken __name__ handling.

PageTemplateFile now using Item_w__name__ mixin, making getId()
and absolute_url() actually work.

When a VHM is activated, it adds the mapping 'VIRTUAL_URL_PARTS': (SERVER_URL, BASEPATH1, virtual_url_path) to the request's 'other' dictionary.  If BASEPATH1 is empty, it is omitted from the tuple.  The joined parts are also added under the key 'VIRTUAL_URL'.  Since the parts are evaluated before traversal continues, they will not reflect modifications to the path during traversal or by the addition of a default method such as 'index_html'.

Collector #1012: A carefully crafted compressed tree state could violate size limit.  Limit is no longer hardcoded.

This was the Python 2.1 support for RestrictedPython.

Collector #809: Added and documented Traversable.py methods absolute_url_path and virtual_url_path, and reverted earlier change to absolute_url behaviour.

- removed unused imports