Update gitignore
Set up basic go-lang project structure

Created a Rakefile to assist in build tasks
The main package will be called "slartibartfast" for now
Set up an environment file to ensure GOPATH and PATH get set nicely
Pull in go-gl/gl and go-gl/glfw, and added test script

GLFW abstracts platform-specific setup requirements to get an OpenGL
context, including input handling, and gl is OpenGL.

I'll be keeping all used libraries in the repository to start with, as a
way of being absolutely sure that I'm always using a version of a given
library that works with this application.
Add simple library installation handling to Rakefile