Wikidata deployment

Rationale
See Wikidata for more information about the Wikidata project generally.

Core changes
Wikidata patches awaiting review:


 * Gerrit 14084 - Adding ll_local to languagelinks table
 * Currently awaiting comment from Jeroen. Current approach has -2.
 * Gerrit 14295 - Adding sites handling
 * Currently awaiting comment from Jeroen and/or Tim.
 * - Merging the Wikidata branch (ContentHandler)
 * Currently awaiting review by Tim

New extensions
The whole Wikibase code (4 extensions: repo, client and shared code in lib and diff) needs a review
 * Repo
 * Lib
 * Client
 * Diff

Also, we want to deploy Extension:Stick to That Language, see

Miscellaneous

 * Wikidata/2005 proposal - original 2005 proposal for Wikidata