This changes the node API to work with multiple elements, so we can
support about groups. Instead of passing in and returning single DOM
elements, we use arrays of DOM elements.
ve.dm.Converter:
* Pass modelRegistry into the constructor
* Remove onNodeRegister handler and its data
* Remove getDataElementFromDomElement() and
getDataAnnotationFromDomElement(). Most logic moved into
getDataFromDom(), some into createDataElement()
* Remove createAlien(), replaced with
createDataElement( ve.dm.AlienNode, ... )
* Replace doAboutGrouping() (which wrapped about groups) with
getAboutGroup() (which returns an array of the nodes in the group)
* Put in a hack so <meta>/<link> elements with an mw: property aren't
alienated
* Remove about group wrapping behavior in favor of just outputting
multiple nodes
ve.dm.AlienNode.js:
* For multi-element aliens, only choose inline if all elements are
inline, not just the first one
ve.dm.example.js:
* Add html/0 stuff for meta nodes
* Fix test case to reflect new alien behavior
Change-Id: I40dcc27430f778bc00a44b91b7d824bfb2718be6
Defaults to false, nodes can opt into about grouping. Not being used
yet, will be used in the converter rewrite.
Change-Id: Ic2a529241e69fb07ac926c826ead0108193b3050
