The purpose of this PR is to unify the versioning mechanics ofParserProxy and theBaseParser in a new interface calledparse withinParserProxy.

#prevextraction=parser(crawl_date).parse(html, ...)#nowextraction=parser.parse(html,crawl_date, ...)

This change is primarily a preparation for an upcoming feature that will enable contributors to deprecate individual attributes.

Update: Maybe that's not really necessary