Fill the new partition_root field when from migrating older databases.

Fix request scope inside instance trees so that an instance is uniquely
identified by its name and the partition of the instance tree's root.

In other words, this allows diamond-shaped instance trees.

Test that there cannot be two sub-sub-instances with the same name
within the same instance tree, i.e. that we can form diamonds.

See merge request nexedi/slapos.core!480

See merge request nexedi/slapos.core!485

  ... to make publication_url happy

   Since the accounting workflow introduced Guard on start transition, it is required
   assignee or assignor to change the state (before Modify Portal content was enough).

   The script is invoke as Shadow user, and since destination section is set, the User
   automatically become Auditor (rather them Assignee) so it would imply a deeper
   change to relax security for the shadow user (not shadow person) just to invoke start.
   Not to mention HUGE security update to be done.

   Use Manager proxy role is not ideal, but it doesn't introduce a security issue while
   solve the problem until a deeper review on the roles for Shadow users takes place.

   Export last workflow state for Business Processes

See merge request nexedi/slapos.core!481

   Since instances typically only access master once a day, double the cache duration to ensure it wasnt flushed between the runs.

   The verification is somehow duplicated with the ComputeNode_checkSoftwareInstallationState.

   The script to check Software Installations already expose problems whenever a
   new software is requested and not built properly, which is the focus of the
   verification removed by this commit.

  Update script to handle also stalled cases

See merge request !477

Read from stdout or stderr only when the event returned by the
selector guarantees that the read will be non-blocking.

Switch to using high-level selectors API instead of low-level
select/poll.

See merge request nexedi/slapos.core!473

   Otherwise capacity is closed due lack of access.

   There is no reason to handle capacity in a different way for personal or friend. This comply with the future design, so keep all consistent by only differentiating Open and Close allocation scope whenever update capacity.

See merge request nexedi/slapos.core!472

   This automatic updates arent required anymore, since we do not intend to have public machines anymore.

See merge request nexedi/slapos.core!443

See merge request nexedi/slapos.core!470

See merge request !471