(bug 30269) Strings like foobar//barfoo are linked to become foobar[//barfoo]

(bug 30269) Strings like foobar//barfoo are linked to become foobar[//barfoo]

* Introduce a boolean parameter to wfUrlProtocols() which, if set to false, will cause '//' to be dropped from the returned regex so it doesn't match protocol-relative URLs
* Introduce wfUrlProtocolsWithoutProtRel() as a wrapper for wfUrlProtocols( false ). The latter should not be used directly because the former is much clearer
* Use this new function in Parser::doMagicLinks() to fix the original bug. Also use it in ApiFormatBase::formatHTML() and CodeCommentLinker::link(), which probably had similar bugs