Initial working version of vcloud-disk_launcher

As per the README:

vCloud Disk Launcher
====================
 
A tool that takes a YAML or JSON configuration file describing a list of
Independent Disks in a vCloud Director Organisation, and provisions them
as needed.
 
### Supports

- Configuration of multiple Independent Disks with:
  - custom name
  - custom size
- Basic idempotent operation - disks that already exist are skipped.
- Adds helper code to prevent creation of disks with the same name.

### Limitations

- Does not yet support configuration of the storage profile of an independent
  disk. The default storage profile for the vDC is used.