3D Scatterplot with csv upload

This is the second in a series of 3D scatter plots rendered using webGL. The first example used static data stored on the server whereas this example allows users to upload csv files. The files need to be in the following format:

Var 1a	Var 2a	Var 3a	Var 1b	Var 2b	Var 3b	Var 1c	Var 2c	Var 3c
x1	y1	z1	x2	y2	z2	x3	y3	z3
235	597	487	232	593	156	325	945	332
458	702	724	735	152	717	273	350	598

And if you don't have any data formatted just that way you can use [this csv file](https://gist.githubusercontent.com/phil-pedruco/9852362/raw/6764ed563711fa42dae37bf61f2c4e31a75b13cc/defaultData.csv). Note that you can only upload one csv at a time. If you want to view another csv just refresh the page.

You can change view by rotating cube using the mouse, move it left and right to rotate the cube around the y-axis and up and down to rotate it about the x adn z axis's. At present there's no relationship between the colours of the particles.

The visualisation uses the fantastic threejs library for the 3D and hooks into webGL. The example presented here is heavily based on the threejs scatter plot example. I've also used d3.js for some of convenience functions to import the data, scale the data and set up the ranges for the axis's.