Adds a new flag to VM metadata to allow setting the VM live migration
max downtime. This will enable very busy VMs that hang live migration to
have this value changed.
Move the old manage script to _legacy, and add a new _flask version with
modern Flask tooling. Decide which one to call via pvc-api-db-migrate
using /etc/debian_version call.
Add management of the pvcprov database with SQLAlchemy, to allow
seamless management of the database. Add automatic tasks to the postinst
of the API to execute these migrations.
Joshua Boniface