Use compiler's inputFileSystem for reading the source files and sourcemaps.

[Arnavion]

Fixes #2

[sokra]

Yeah... I see what you want to do...

But _compiler is a private API, so we better expose the inputFileSystem as this.fs to loaders. Would you like to do a PR there. This affects more loaders as many of them use require("fs"). this.fs could automatically track dependencies too...

[Arnavion]

That makes sense. I'll do that.

Edit: webpack/webpack#732

[fzaninotto]

It doesn't seem to be enough. Although a webpack build on fs works, with your patch a webpack-dev-server fails with the following error:

        callbacks[i].apply(null, args);
                     ^
TypeError: undefined is not a function
    at Storage.finished (path/to/node_modules/webpack/node_modules/enhanced-resolve/lib/CachedInputFileSystem.js:38:16)
    at evalmachine.<anonymous>:334:14
    at path/to/node_modules/webpack/node_modules/enhanced-resolve/node_modules/graceful-fs/graceful-fs.js:102:5
    at FSReqWrap.oncomplete (evalmachine.<anonymous>:95:15)

[Arnavion]

@fzaninotto Sorry, I don't use webpack any more so I'm not going to push for this. Maybe try seeing what exactly callback[i] is (presumably not a function) and how it came to be there.

[Strate]

What's here? Why just not to merge it?

[jedwards1211]

@sokra if _compiler is private API for loaders but not for plugins, perhaps this should be some sort of plugin/loader hybrid instead?

[Arnavion]

I'm not using webpack any more and have no idea if this PR is still valid or not, so I'm closing it. If someone else needs it please feel free to submit your own PR.