Find if and where a light ray intersects a triangle (in 3D of course). This is optimized for speed. See nice general explanation here

`Pkg.clone("git://github.com/JuliaGeometry/TriangleIntersect.jl.git")`

#Usage Import and create some points:

```
using TriangleIntersect
a = Point(0,0,0)
b = Point(1,0,0)
c = Point(0,1,0)
```

Create a triangle

`t = Triangle(b,a,c)`

Cast a ray:

`r = Ray(Point(0.1,0.1,1), Point(0.1,0.1,-1))`

Check the intersection:

`intersect(r, t) # -> Intersection(Point(0.2,0.2,0.0),1.02,true)`

The `Intersection`

type is simply defined as:

```
immutable Intersection
ip::Point # intersecting point
id::Float64 # intersecting distance
is_intersection::Bool
end
```