Enhancement: Including GLFW as a submodule

[dykatz]

We would no longer have to download GLFW separately for it to work, it would become easier to set up and run, and it would always be up to date.

[fogleman]

How is this accomplished? I'm new to cmake.

[dykatz]

It isn't something done with cmake; it's done with git. This document from the official git site is a pretty good resource for this.

[fogleman]

Done!

[dykatz]

Sweet! You may want to consider updating the read me.

[fogleman]

Hmm, didn't realize that git clone wouldn't recursively pull the submodules. Not sure if I love this approach now.

[dykatz]

I just found this article, which may explain it better. To use git clone recursively, you just need to use --recursive.