Introduce an 'initialize()' function that does the actual init
(session, cookies, config options) and can called separately from
the constructor __init__().
This allows, for example, to adjust config access inside a Job
before most of it already happened when calling 'extractor.find()'.
'/?&#' -> '/?#' and '?&#' -> '?#'
According to https://www.ietf.org/rfc/rfc3986.txt, URLs are
"organized hierarchically" by using "the slash ("/"), question
mark ("?"), and number sign ("#") characters to delimit components"
Mike Fährmann