Supervisord files of stopped partitions (only those) should be removed,
and those of started partitions should exist.

Create the supervisord configuration file for the partition's processes
on start, and remove it on stop.

Give each supervisor process group its own separate configuration file.

See merge request nexedi/slapos.core!519

See merge request nexedi/slapos.core!517

   Ignore to check if price matches if the invoice was created manually, and not linked to a business process.

See merge request nexedi/slapos.core!516

Improve hateoas support to show shared instances.

It turns out that ERP5 returns
```
'form_id': {
  'type': 'StringField',
  'key': 'form_id',
  'default': 'InstanceTree_viewAsHateoas',
},
```
for the `form_id` in hateoas, so adapt the proxy to do the same.

Currently hateoas support in proxy only lists non-shared instances,
so this always says that the instances are not shared.

See merge request nexedi/slapos.core!511

See merge request nexedi/slapos.core!514

   Set it non-editable

See merge request nexedi/slapos.core!513

See merge request nexedi/slapos.core!509

   This script isnt used at all

See merge request nexedi/slapos.core!504

   Strict returns directly a single Software Release for a giving url.

   This fast input option aims to allow certain sites, request "related" slaves
   from an Instance Tree.

   The script  InstanceTree_getFastInputDict is used to custom the feature to
   specific software releases, since depends which one is used, and it cannot
   be generalized for now.

See merge request nexedi/slapos.core!505

See merge request nexedi/slapos.core!506

See merge request nexedi/slapos.core!508