Start of renderer rewrite
Add shadow mapping stage
Add lighting stage
Add render transparent models stage
Add shininess to materials texture

Value of 0 corresponds to 0 exponent, 1 to 100 for specular term
Fix typo
Only update chunk meshes if the chunk is visible

Also, use random colours for solid models to view when chunks are
updated
Change order of instructions in interface tick

Start by updating the camera from the input,
Next update the chunk models,
Next the lighting,
Then render,
Finally update the snapshots