Avoid use Popen.communicate instead of SlapPopen to run promises,
because SlapPopen uses threads and preexec_fn is not thread-safe.

The drawback is that logs are not propagated in real-time anymore,
but only once the promise process completes.

When a forwarded partition is requested in destroyed state, delete
the entry from forwarded_partition_request table (after getting reply
from remote server)

See merge request !400

  Ensure that all files exists and are reacheable.

  Include also the front page to be displayed

  Customize front page for target the administrator.

See merge request nexedi/slapos.core!447

   Since they are commonly overwritten on project context, keep it on ignore list.

The frontend software URL is a virtual URL that does not have a
corresponding schema, so fetching the schema is just a waste of time.

Generally speaking, fetching the schema impact performance a lot, so it
would be nice to cache them. In practice most of the requests made
during instantiation are frontend request, so this is a first easy step
to fix the performance impact of fetching the schema.

See merge request nexedi/slapos.core!445

   Force properly the creation of the invoices and assert if links are correctly displayed.

    The value isn't fetch from a getAttachment anymore

Apply suggestion to master/bt5/slapos_accounting/SkinTemplateItem/portal_skins/slapos_accounting/AccountingTransactionModule_getUnpaidInvoiceList.py

   It is required to show them all before continue

   There isnt a need to fetch on every line, since the information comes from options

  On invoices tab, only display invoices Unpaid (missing payments).

  This makes easy the user know what is pending to pay and on the 'List all' tab, he can
  search old invoices (and view them all by date)

See merge request !444

   Ensure it wont find any unexpected published notification message.

   This fails if the website property is set on Live Tests or whenever you run on project specific context.

See merge request !438

   Delay a bit before edit for now.