Fixed a problem in setting user permissions.

get set even if we fail setting traceback.

We can't pretify it, but at least we can restart.

care of it.

This is a pretty significant restructuring of ZPublisher to
allow a new module hook for handling errors.  There are two goals
in this:

  - To allow Zope to retry a request when ZODB raises a ConflictError, and

  - To move reformatting of exception using standard_error_message
    out to the publisher level so that:

    - Errors don't get obfuscated by error handling done by
      sub-documents and external methods, and

    - Errors raised by the publisher (e.g. for input errors,
      not-found errors, system exit, etc) get prettified.

processInputs that is called by the publisher at the start of request
processing. Any request processing that can raise errors must be
defered at least until this method is called so that the publisher can
handle the errors. BaseRequest now has an empty implementation for
this method and HTTPRequest defers most of it's initialization to this
method.

This fixes a bug in handling of form inut errors, which were being
raised as ZServer server errors.

a feature.

-Michel

Now medusa's http server is better about handling broken HTTP requests. It now tries to figure out a reasonable request, and failing that it returns a 400 error.

This patch has been submitted to Sam Rushing.

Added a -r switch for read-only operation. In read-only mode ZServer won't write any pid or log files. The mode is only really good for running in weird environments, like off a CD.

Fixed problems with product permissions registration methods that caused product permissions to get lost when adding, changing and deleting permission objects.

Restructured _str using continue to avoid excessive nesting.

sql method is called in a version.  Column meta-data
should (and is now) only computed when an sql method is tested.

version.