Updated mediawiki/extensions
Project: mediawiki/extensions/Wikibase  4c9998562bf0829f8f192dd806327d0f8e2f26fd

statementview/snaklistview refactoring

Removed redundant code from statementview and snaklistview and moved some documentation.
The statementview widget does not trigger its own API request saving a (new) reference
anymore. The statementview-specific code reacting on adding a new reference has been
moved to the "afterstopediting" event handling.

Change-Id: I4b6ccc8873273c8b319a129980bf745185569679