Shallow run

Is there any way to run browserify on a file/stdin, skipping all bundling steps and just applying a transform/plugin? That would enable browserify for other bundling systems, like [ncc](https://github.com/zeit/ncc) or [rollup](https://github.com/lautis/rollup-plugin-browserify-transform) as a transform CLI tool. _ncc_, for example, is incapable of handling glslify.

There is [browserify-single-file](https://ghub.io/browserify-single-file) package for that purpose, which seems to be broken. That can be fixed to match the current API, but that will be outdated with the next browserify release, also that emulates just a part of browserify API, which likely makes most of the plugins unavailable for it.

A flag `--shallow` (`--no-bundle`, `--bypass` or alike) would be a natural extension of `--bare` / `--node`, and similar by output to `--list` or `--deps`.

@goto-bus-stop would you consider this a good feature?