Upgrade to new glslify

[jakepruitt]

In order to get esprima-six out of the dependency tree (refs #149), we need to remove references to old versions of astw, which are found in the old versions of glslify, gl-compare, and gl-axes. The interface to glslify has changed since version 1, so these will need to be changed in all of these examples.

I can start sketching this out, and at least follow the migration steps in glslify. I'm not too familiar with modern best practices of browserify, and I don't have any experience working with GL, so I'll probably need help and lots of 👀 for review.

cc/ @mikolalysenko @mattdesl @hughsk

[jacob-meacham]

@jakepruitt I started this tonight, actually - initial work in a couple of modules (glslify-live, gl-compare) are up, but there is quite a bit more work to do - especially in glslify-live

[jakepruitt]

@jacob-meacham sweet! Yeah, I was working on this last night too, especially the bundling in glslify-live. I'll let you know if I get any solid progress.

[jacob-meacham]

Initial shader-school work is in #151 - all exercises now work, minus glslify-live