star: Support an optional seed_base for new planets

Pass in any URL that can be appended with "/{meta,user}-data" and return
valid cloud-init stuff
colony: Initial cloud-init support
star: Automatically mount ships
WIP: auto-mount ship
planet: Include status in struct

Closes #2
planet: Make deathstar hard shutdown
planet: Fix template for VMs

Still to-do: Automatically add the installation `Ship` to the VM
ship: Make download() sync
star: Make planet() sync
ship: Make Star a borrow
star: Implement Clone on NewPlanet
ship: Implement Clone
star: Change ship field to shasum
star: Add struct for new Planet HTTP requests
planet: Add further state management

- Force shutdown/reboot
- resume

Closes #1
planet: Implement Display for Health
planet: Make status functions public
star: Allow for getting planets based on UUID