Fix for #2288: do not quote + and @ characters when forming BaseRequest and HTTPRequest URL variables

Raise SyntaxError when encountering invalid PythonScript headers.

See http://mail.zope.org/pipermail/zope/2007-February/170537.html

in the Z3 world

context of the current object

lot, but even better, we should take further steps towards using the z3 publisher.

in zope.tal.xmlparsers.XMLParser.parseString()

that will raise an exception (undetected so far)

o Forward-port from 2.8 branch.

o Forward-port from 2.8 branch.

  Log message for revision 71846:
    Back out accidental commit from yesterday