Allow Self-Service User to create and restore Snapshot

[fufroma]

xo-server 5.2.4 / xo-web 5.2.2

As a Self-Service User, i'd like to have the ability to create and restore snapshot of my VM.

I know this is tricky to implement on a dev POV, but would you agree to have this issue open in "Long Term Self-Service Enhancement" ?

Related to #1525

[olivierlambert]

"Due by June 6, 2017". Almost there \o/

[julien-f]

Limit usage computation is similar to VM:

• even for storage because it's too complicated to distinguish between thin and think provisioning
• except for live resources (CPUs, memory, etc.)

[fufroma]

As you closed #1865, can't you do something for this one ? ❤️

[olivierlambert]

I think it's not the same thing (to do in the code, not the same amount of work at all). Do you confirm @julien-f ?

[pdonias]

Closing in favor of #3304.