Name already in use

Also with other minor enhancements.

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

The container is now built directly from the root directory.
Even the simplest composition was moved to demo/plain.

(only a dummy test for now)

By setting CREATE_NEW_DATABASE to "if_needed" we avoid re-running
of database initialization code in midpoint-data container on
re-creation of that container. (Although almost harmless it could
cause problems in some situations.)

1) There's now a cleanup step before and after running the tests
2) Tests check their results more thoroughly
3) Until MariaDB is changed, a temporary solution for down-up issue is present

However, it requires PR docker#7 from docker/mariadb repo to be accepted
in order to function.

Added
 - 110: get administrator
 - 120: add+get user
 - 200: stop+start containers (failing, but ignoring that)
 - 300: repository preservation (disabled)

It was not easy to build two Docker images in TIER Jenkinsfile
(using docker/util). It seems that tier/mariadb:mariadb10 is OK to be
used with midPoint without any customizations, so we use it.

This was for testing the logging requirement concerning UTC timestamps.

Note: it does not work with Shibboleth authentication yet.

This is to avoid Shibboleth problems when opening
http://localhost/grouper instead of https://localhost/grouper.

Building is now more straightforward and better documented.
To quickly see timezone problems we have set Central timezone
for various containers.

It is superseded by "demo/complex" scenario, basically
having the same content.

This is a rework/update of the original "Grouper-midPoint" demo.
It is a work in progress. Do not use yet.

Changes in the midPoint Docker container:
1. Logging is improved: now we provide TIER-style logging for
   both midpoint.log content and plain console output. (Note that
   not all entry timestamps are in UTC yet.)
2. Reverted some of TIER beacon changes to make it more compliant
   with TIER standards: shell file names, opt-out environment variable,
   collector server name+port.

These changes are: Zulu JVM, logging fixes, TIER Beacon.
The crond is now running in foreground to avoid "can't lock
/var/run/crond.pid" messages.

...and added slack notifications as well.

...and added missing LOGOUT_URL one.

…/TIER/midPoint_container into shibboleth-integration

Now the default port is derived from the database type.
Also, PostgreSQL demo was cleaned up.