General improvements

* Allow for inline shaders using the `inline` flag.
* Allow using `frag` and `vert` as shorthand options.
* Expose glslify transform streams from the browserify transform.
* Update glslify-stream: `0.0.1 -> ^0.2.1`

@chrisdickinson let me know if you have any input on this, otherwise will merge in a couple days :) Thanks!