previewer: d3js csv previewer

* Adds d3js csv previewer.

Signed-off-by: Adrian Pawel Baran <adrian.pawel.baran@cern.ch>
Shall we wrap it as proper plugin?

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What about D3 + require.js: http://stackoverflow.com/questions/13157704/how-to-integrate-d3-with-require-js , http://bl.ocks.org/jasondavies/37e8d3ec0c5125e7e5dd