Updated mediawiki/extensions
Project: mediawiki/extensions/WikibaseDatabase  dd51e1538494d0779af4e5de312c736c5a959a69

Add various todos accross the component.

These todos have come from
 - reviewing code (including escaping)
 - testing various methods
 - reviewing test coverage

Change-Id: I3520372b8d958a60120a00d0ce4c7012dbb8f8cb