Ditch Gulp entirely

[Silic0nS0ldier]

While working on #2 I've noticed that this plugin doesn't work like existing Gulp plugins, much to its own detriment.

1. The configuration file is provided via gulp.src, only to have to be read again (path is pulled from the Vinyl object, then require is used).
2. gulp.src is used internally, per bundle. If a file is included in multiple bundles, it'll need to be read several times.
3. How the plugin works stunts any efforts to further stabilize and optimize builds in UserFrosting. If the plugin works on files exclusively in the pipeline, then it will be possibly to revise the build process to cut bundling time in half while greatly reducing IO.

[Silic0nS0ldier]

See #6