Adding swix

I'm currently developing an iOS machine learning library with the goal of easy Matlab-iOS conversion. This library includes a general matrix language as well as some OpenCV wrappers.

An example:

```swift
var x = randn((4,4))
var y = inv(x)
assert(x *! y ~== eye(4))
```

Currently, this library is very rough and under active development but the basic framework is nailed down. Since it's under active development, there are still large speed gains to be made that are easy to implement.

[knn]:https://en.wikipedia.org/wiki/K-nearest_neighbor_algorithm
[svm]:https://en.wikipedia.org/wiki/Support_vector_machine
[pca]:https://en.wikipedia.org/wiki/Principal_component_analysis
[svd]:https://en.wikipedia.org/wiki/Singular_value_decomposition