This means we don't have to rely on data-rt.sHref. It also means that
we'll now be showing the canonical link target in the link inspector
rather than the link target as entered by the user, but that's fine.
Also change test to have href differ from sHref to show that we use
href.
Change-Id: Idabdbf2579663ef1efb47d6a73f39743c9f64f3b
This is ugly but makes things work again. I intend to clean this up once
we have a better attribute API
* Recognize mw:WikiLink, mw:SimpleWikiLink, mw:ExtLink,
mw:NumberedExtLink and mw:UrlLink
* Support is incomplete because we can't get to the annotation text with
the current API
* Preserve all unhandled attributes rather than special-casing data-mw
* Update remaining code using data-mw (sHref and stx extraction) to
account for the data-mw -> data-rt rename
* Update tests accordingly
Change-Id: Ia13d3008a6d4cdc8828f9acda5aa797566bc597f