Remove glfw so I can add it with git subtree.
Squashed 'glfw/' content from commit e4d3f86

git-subtree-dir: glfw
git-subtree-split: e4d3f860977baa314f022d7db5ed3420389ba372
Merge commit '1497b833b4e008c63dd4094c408330eb84a90ce2' as 'glfw'
Remove glm and gli so I can add them with git subtree.
Squashed 'glm/' content from commit 4fa38c7

git-subtree-dir: glm
git-subtree-split: 4fa38c7a03df4064f9c4fff75f9d5a93f0049ae5
Merge commit 'f41175c6b165e20ef9b0d27af67417ecabc10a74' as 'glm'
Squashed 'gli/' content from commit 93c0c44

git-subtree-dir: gli
git-subtree-split: 93c0c449dab34039800d00dd7e36aba98fa59b49
Merge commit '948900cfd4228e188cdb585ace9f9156c87fe338' as 'gli'