Updated mediawiki/extensions
Project: mediawiki/extensions/SemanticSifter  ce7d882b5e273288f253cad8d30795f663939206

Consistency tweaks in preparation for adding extension to
translatewiki.net

* Add header
* Rephrase description message
* Tweak to message documentation

Change-Id: I63b16c7be4e533328d1495f494ecf98c16f1c782