Changed Scene from typeclass into data type
Modified Camera to be more general

Camera instances now work on any properly specified Scene object.
Removed addObject from generic Scene type

For lit scenes, objects require additional information
before being added.
Added eval function to Geom

Allows you to evaluate a Ray with a scalar distance to obtain a
Point.
First pass at Light.hs

It type checks, so that's a large part of the battle right there.
Phong shading in the scene implemented

Looks pretty good, but possibly need to tweak specular exponent.
The cylinder seems to be casting some wierd shadows as well.

Fixed the speckled shading (floating point error) by adjusting the
origin of the shadow ray by epsilon * normal
Tweaked specular exponent for more focused shine
Fixed cylinder intersection to ignore omega < 0

Also changed cylinder color to yellow
Added extra scene with another light

extraLight adds a red light in the bottom left
Merge branch 'next' into 4d
Handful of basic stuff.

Needs more work!