tmcw/simple-statistics — pull request #50 by rluta (2013-11-27 21:18:54+00:00)
Title: Extend quantile function to accept an array of quantile parameters

This patch extends the quantile function to accept as an alternate form an array of input quantile parameters and in this case returns an array of quantile values in the same order.
The parameter range has also been extended to accept p=0 and p=1 which respectively return the min and max value in the distribution.

When dealing with large arrays, it's a useful performance optimization in common quantile use cases such as calculating Q-Q plot or boxplot statistics.

Exemple syntax
```
var odd = [3, 6, 7, 8, 8, 9, 10, 13, 15, 16, 20];
assert.deepEqual(ss.quantile(odd, [0,0.25,0.5,0.75,1]), [3,7,9,15,20]);
```