Add support for a loopback Vchan module, to satisfy the Conduit functor
Add a `VCHAN_xen` module that maps a working vchan implementation
Merge pull request #305 from avsm/master

Alias Console to Console_unix and Console_xen
Merge pull request #300 from avsm/vchan-conduit

Add Vchan support to Mirage config.ml
Correctly show config file locations when using a custom one