Updated the network-node part
Updated network flat mode text.
Add ansible playbooks to check the configuration of the real nodes
Merge branch 'master' of github.com:gc3-uzh-ch/gridka-school
fix typo
add newline at the end of the inventory file
Cosmetic changes
Changes on the information about the network configuration
Move down network layout diagram
Update network diagram
Add plays for checking virtual machine images
Add a few more info about RabbitMQ and glance
Add exercises
Update network diagram
Updates bellow

* removed Recap section, 
* fixed a typo in network setup section,
* remove an unconsistent line.
Add openstack conceptual arch image and make MySQL listen to 10.0.0.3
Cosmetic changes
Minor changes
Update doc for use of tgt instead if iet
Merge branch 'master' of github.com:gc3-uzh-ch/gridka-school

Conflicts:
	tutorial/tutorial.rst