Revamped site links related JavaScript

Replaced legacy code managing the site links with code that conforms to the current architecture.
SiteLinksEditTool, EditableSiteLink, SiteIdInterface, SitePageInterface are replaced with
jQuery.wikibase.sitelinklistview and jQuery.wikibase.sitelinkview.

Requires DataModelJavaScript 0.3.2
https://github.com/wmde/WikidataBrowserTests/pull/3 should be merged along with
this change to keep the browser tests working.

Change-Id: Iabda9f74690f4d26c49b6653f2c0ce4cad075dec
Merge "Revamped site links related JavaScript"