* @ResponseBody Annotation for JSON Response
* Old ARSnova Servlet does nothing
* New Spring Servlet loads Beans, Services, Security and SocketServer
* One Property Loader which is used in XML Spring Configuration and with
@Value Annotation

With this configuration both
 - spring security setup
 - bean properties
will be set to values defined in /etc/arsnova/arsnova.properties.

Admins ARE REQUIERED to create production settings file by given example
in /etc/arsnova.

This MUST be done because local developer settings ARE different to
the given example settings.

Deployed settings MUST be prepared by build process to match production
environment.

DO NOT expect local example settings will match all production settings.

user gets back to the right arsnova

cleanup is now working as expected

* remove client from map on disconnect

This reverts commit 04bd8274.

Conflicts:
	src/main/java/de/thm/arsnova/services/SessionService.java

* If a user posts new feedback, while having already posted one, the value
gets updated. This prevents feedback adding up.
* If feedback is too old (10 minutes), it gets removed. For testing
purposes the cleaning routine currently runs every few seconds, and
feedback only lasts a few seconds as well.
* The deleted feedback changes are broadcasted to:
	o All users, if feedback of other users has been deleted.
	o The user whose feedback got deleted.

Currently, this is a huge mess! There are three types of "Session Ids":
* The Socket.IO "session"
* The internal CouchDB session id
* The ARSnova session keyword

A severe clean up is needed before proceeding any further...

properties loaded from local filesystem

remove websocketcontroller and let sessioncontroller do the
authorization
add toString to User entity

in session stored referer

Conflicts:
	src/main/java/de/thm/arsnova/socket/ARSnovaSocketIOServer.java

Properties from properties file are available in all beans now.
CouchDB connection in SessionService will be created using these settings.
If a connection fails, the next request will have a new try instead of
throwing an exception.

leiten