Add OHLC/Candlestick charts to core dc.js library

Add OHLC/Candlestick charts to core dc.js library
http://dc-js.github.io/dc.js/docs/html/

Reference:
http://www.primefaces.org/showcase/ui/chart/ohlc.xhtml

[gordonwoodhull]

There was a start at this in #626, which links to a fork with a first (abandoned) attempt.