This is basically a clone of demo/complex2s from the laboratory branch.

Main differences:

1. Fixed "unknown host directory" error message when building
grouper_data container. The initialization script is no longer run
at build time in grouper_data. It is instead run at first start of
grouper_daemon container, when LDAP server is already up.

2. banderson and sysadmingroup is now created when building LDAP container.
So the Grouper resource test action can be executed directly, without
the need to prepare midPoint objects for banderson & sysadmingroup first.

Note that tests were not updated yet.

$tag is now defined in common.bash and used throughout building scripts.
The goal is to allow building and testing both from Jenkins and standalone.

build.sh is now more generic; allows rebuilding if -r is specified.

The demo directories were shown incorrectly.

Also disabled auto-restart of midPoint (causes problems
if midPoint cannot be started).

Also with other minor enhancements.

1. demo/plain -> demo/simple
2. updated README.MD