Wikipedia River

Hi,

I just pushed support for a wikipedia river, here is the issue:
http://github.com/elasticsearch/elasticsearch/issues/closed#issue/403. It
basically automatically start downloading wikipedia dump and index it on the
fly. Not the fastest way to do it (the download aspect, and the parser I
found is not the most optimized one), but can be interesting to use as a way
to get some data into elasticsearch to play with (as is the twitter river as
well).

-shay.banon