Accept fs module API to define methods

[piranna]

Allow to give a fs-like object to define the methods. This could allow to easily export fs objects like the one provided by webdav-fs and others.

[piranna]

I've taken a better aproach to this, and decided to create a module that interconnect both APIs. fs-fuse allow to use any fs-like object as a FUSE filesystem, and also has a CLI compatible with the mount command so you only need to tell it the path to your module so it can be required and exported.

I think this issue can be clossed now, but probably it could be useful to give a reference to fs-fuse on the readme file, what do you think? :-)

[mafintosh]

Very cool! Send a PR that links your module

[piranna]

Done :-)