docker: initial release

• Initial release of Docker configuration. docker-compose build rebuilds the image, docker-compose up runs the Invenio demo site, docker exec -it invenio_web_1 /opt/invenio/bin/inveniocfg --run-unit-tests runs the unit test suite, etc. (closes #2736)

• NOTE Uses CentOS-5 with Python-2.4 and embedded MySQL-5.0 server, fitting minimal requirements asked for Invenio v1.0 release series.

• NOTE Installs MySQL DB server inside the main web container, as there is no official MySQL-5.0 docker image out there yet.

• Amends inveniocfg.py to handle 0.0.0.0 style of IP address.

Signed-off-by: Tibor Simko <tibor.simko@cern.ch>