Refactor core to accept new formats

[jimkont]

Wikidata introduced JSON as a new wiki text format. To accommodate this change and be prepared for the next formats that will follow @jcsahnwaldt suggested a number of refactoring actions.

There are described in pull request #35 as well as in this developers thread

Pull request #35 also contains 2 drawings on the current extraction design and the new one we want.

This work is estimated from 1 day (minimum) to 1 week (maximum)

[jcsahnwaldt]

I fixed the link for the formats: http://www.mediawiki.org/wiki/Manual:ContentHandler/Doc#Serialization is correct, it lists the formats that MediaWiki knows in general. http://www.mediawiki.org/wiki/API:Data_formats just lists the formats that api.php may return.

[jcsahnwaldt]

This may be obsolete, since Wikidata now publishes RDF, e.g. http://www.wikidata.org/wiki/Special:EntityData/q1.nt / http://www.wikidata.org/wiki/Special:EntityData/q1.rdf etc. Dumps will probably come soon as well. Also see http://lists.wikimedia.org/pipermail/wikidata-l/2013-May/thread.html#2205