Adds the following Wikipedia custom functions for use in Google Spreadsheets:

- WIKITRANSLATE: Returns Wikipedia translations (language links) for a Wikipedia article.
- WIKISYNONYMS: Returns Wikipedia synonyms (redirects) for a Wikipedia article.
- WIKIEXPAND: Returns Wikipedia translations (language links) and synonyms (redirects) for a Wikipedia article.
- WIKICATEGORYMEMBERS: Returns Wikipedia category members for a Wikipedia category.
- WIKISUBCATEGORIES: Returns Wikipedia subcategories for a Wikipedia category.
- WIKIINBOUNDLINKS: Returns Wikipedia inbound links for a Wikipedia article.
- WIKIOUTBOUNDLINKS: Returns Wikipedia outbound links for a Wikipedia article.
- WIKIMUTUALLINKS: Returns Wikipedia mutual links, i.e, the intersection of inbound and outbound links for a Wikipedia article.
- WIKIGEOCOORDINATES: Returns Wikipedia geocoordinates for a Wikipedia article.
- WIKIDATAFACTS: Returns Wikidata facts for a Wikipedia article.
- WIKIDATAQID: Returns the Wikidata qid of the corresponding Wikidata item for an article.
- WIKIPAGEVIEWS: Returns Wikipedia pageviews statistics for a Wikipedia article.
- WIKIPAGEEDITS: Returns Wikipedia pageedits statistics for a Wikipedia article.
- WIKICOMMONSLINK: Returns the Wikimedia Commons link for a file.
- WIKICATEGORIES: Returns Wikipedia categories for a Wikipedia article.
- WIKIARTICLESAROUND: Returns Wikipedia articles around a Wikipedia article or around a point.
- WIKISEARCH: Returns Wikipedia article results for a query.
- WIKIQUARRY: Returns the output of the Quarry (https://meta.wikimedia.org/wiki/Research:Quarry) query with the specified query ID.

You can see a demo of all functions in the demo spreadsheet https://docs.google.com/spreadsheets/d/1sVduZul787O-bRzuy0UKpRl7bkouxwaIOsxXuJGm6yg/edit?usp=sharing.

The source code of the Wikipedia Tools is available on GitHub: https://github.com/tomayac/wikipedia-tools-for-google-spreadsheets. Please post feature requests and report issues on GitHub as well.

A paper with use case descriptions is available on arXiv: http://arxiv.org/pdf/1602.02506v1 [PDF].