Added a patching mechanism

This allows to patch the system during setup by creating a docker/kolab/utils/patches directory,
adding some patches there, and then customizing the patch-system.sh script,
resulting in the system getting patched when started.

This is useful to incorporate patches in e.g. a test setup branch (the linode branch for instance),
before they are available in packaging.

Summary:
Create a default test resource

Instead of relying on fallbacks in various places just set the
configuration variables

Update base_dns in calendar.inc.php

Use https for the roundcube backend

Revert "Use https for the roundcube backend"

This reverts commit rK0f46d2ae62ed.

kolab container

Create resource set inetstatus

Ignore the inetuserstatus for now

Set https files url

Fixup

Create and set username/password for localhost and '%'

The localhost one is not accessible over 127.0.0.1

Differential Revision: https://git.kolab.org/D3202