This is a proposal for a fix to#74. It is not elegant but it gets the job done.
The way the NormalModuleFactory is found from the dependencyFactories is probably not the right way to do it, but I don't have a good enough understanding on how to do this stuff, and this is the proposal I was able to come up with:-)

The example environment that this PR is fixing is:
index.js:

require("bundle-loader!./test.json");

test.json:

{ "any": "json file" }

Without this fix, this currently returns the error:

ERROR in ./src/test.json (./node_modules/bundle-loader!./src/test.json)
Module parse failed: Unexpected token v in JSON at position 0 while parsing near 'var cbs = [],
data...'
You may need an appropriate loader to handle this file type.