Replace highcharts with nvd3

[SEJeff]

Highcharts isn't open source and nvd3 is much better along with being open source

[SEJeff]

Just added this project to the graphite docs as well, thanks for opening it up!

[karankurani]

Hi Jeff,

Thanks for the merge! :)

Highcharts is open source - "One of the key features of Highcharts is that under any of the licenses, free or not, you are allowed to download the source code and make your own edits. This allows for personal modifications and a great flexibility."

Its licensing scheme is as follows -
"Do you want to use Highcharts for a personal website, a school site or a non-profit organisation? Then you don't need the author's permission, just go on and use Highcharts."

the quotes are referenced from - http://www.highcharts.com/products/highcharts

We also have written clearance from highsoft to package highcharts as part of the open sourced version of orion. It is also mentioned at the end of our README - "This application may NOT be used for a commercial purpose without purchasing the appropriate license from Highsoft. See above link for more details." - link https://github.com/gree/Orion#highcharts--highstock

[dbow]

Hmm nvd3 looks like a good alternative - I've never liked that Orion's use is restricted because of one third party library/dependency. I don't have time to port it over right now, but if someone else wants to, I'd be open to it!