Updated mediawiki/extensions
Project: mediawiki/extensions/Wikibase  c38baa6e10ce217feb1df59bec0eeb2c9289916b

(bug 62644) Move Snak validation into ChangeOps

NOTE: This uncovers the use of invalid data in test cases.
Several test cases had to be fixed in order to account for that.

Change-Id: Ic65b3459936f85f4aa57b654dbc93ae98ded29ef