Create build artifacts that will assist with running sample mesh nodes in the cloud

[hamishcoleman]

Discussed during a video call. Currently, the only real way to demonstrate or experiment with the mesh node platform is to use physical hardware.

As a first step towards allowing virtual environments (regardless of the virtual implementation - local virtual machines, cloud services or even something more exotic), we should generate artifacts for i386/amd64 platformas - similar to the ARM board image artifacts.

For a xD image, this must be a disk image file - the RD image has some more flexibility, so consider creating a bootable ISO image instead of a disk image file.

To make this artifact more usable, the following should also be considered:

• how to configure multiple network interfaces (one for "LAN" and one for "Mesh")
• what options are possible to pass configuration from a cloud automation platform into the booted system