Change Instance Ownership

The idea here is the allow the instance to be relocated. It can receive
a new user and a new project.

This code allows the changes for a new user and a new project, the user
change needs more verification but the project already has quotas check
and it moves the data of the instance from one project to another.

Implements: Blueprint change-instance-ownership
Change-Id: I393dd725a225d8efbd007dc6035f1b3343b40af6
Change Instance Ownership

The idea here is the allow the instance to be relocated. It can receive
a new user and a new project.

This code allows the changes for a new user and a new project, the user
change needs more verification but the project already has quotas check
and it moves the data of the instance from one project to another.

Implements: Blueprint change-instance-ownership
Change-Id: I393dd725a225d8efbd007dc6035f1b3343b40af6