Templates do not count towards a user's quota and cannot be started.
Staff owners may mark and unmark their VMs as templates, so a staff
user could mark a VM as a template, use the freed quota elsewhere, and
unmark it again: the VM came back without any check, over the quota.
For users with a quota (everyone but superusers), turning a template
back into a VM now passes check_user_quota with the VM's size (one VM,
its vCPUs, memory and disks). If the quota is reached or cannot be
verified, it stays a template and the user is told why. Marking a VM as
a template frees quota and is not checked. The view takes the
per-user quota lock like the other quota-checked changes.
The existing template-flag test gives its mocked VM a size. The new
tests fail on the previous code.
Comments, docstrings and live test names cited item IDs of a roadmap
that is not part of the repository. They now say what is meant, or
nothing where the sentence stands without them. Test assertions and
behavior are unchanged.
change_options set is_template for any owner with is_change; the
"staff only" rule existed only as a disabled checkbox in the UI. A
non-staff owner could mark or unmark templates with a POST, and because a
disabled checkbox is not submitted, a non-staff owner who only edited a
template's title or description silently unmarked it, which lifted the
template-only restrictions.
Only change is_template for superusers and staff (for them an unchecked,
unsubmitted checkbox still means "not a template"); leave it alone for
everyone else.
