Allowing includes to require other named includes

This changes specifically addresses my requirements as mentioned in #382 

Unfortunately, I was not able to find a way to cleanly parse included files as thoroughly as others, so it's pretty limited in that it can only include other named includes/deps. Thus, it works for me, since I only needed to provide a `path` include. However, it won't automatically find other remotes deps (eg: `component/event`) or other local deps. (eg: `./util.js`)

This is enough to satisfy all the plugin use-cases I've considered so far, but it could be a limitation that we want to address in the future if the need arises.