The password and username has to be passed to the others instances and used

Define a simple cache implementation using a Dict (Singleton) to prevent call registerComputerPartition
  multiple times over the sections.

/reviewed-on nexedi/slapos!74

  When create a wrapper for etc/service/my-wrapper placing the 2 files
  at the same folder, cause one duplication at the files added to supervisord, so
  always place the python script wrapper at the bin folder of the buildout.

  Ensure the certificates provided by the user actually valid and match, otherwise prevent it write bad certificates.

This allows enabling replication later without requiring a mariadb restart.
For now, nothing passes the internal server-id instance parameter, so
replication is not.

so that build will not fail if the directory was left during previous
builds.

The promise is-process-older-than-dependency-set still fails
if necessary, but does not kill the zope anymore.

  Using ServerAliases %{SERVER_NAME} would not cause a change of URL to something
  diferent them it was requested.

  Include software-type in order to use multiple forms/schemas for
     the same software-type, like simplified or advanced.
  Include shared to include schemas for slaves.

  A nicer form

because Products.ExternalEditor 2.0.0's dtml is not based on Zope2
OFS's one and it drops icons, sort by last_modified etc in ZMI.