Ensure all API return messages are formated the same: no "error", a
final period except when displaying Exception text, and a regular spaced
out format.
Add functions for uploading, listing, and removing OVA images to the API
and CLI interfaces. Includes improved parsing of the OVF and creation of
a system_template and profile for each OVA.
Also modifies some behaviour around profiles, making most components
option at creation to support both profile types (and incomplete
profiles generally).
Implementation part 2/3 - remaining: OVA VM creation
References #71
