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

* Make guest login working with new UserService
* Reuse existing guest username
* Adapted tests

This method uses transaction level READ_COMMITTED.

switch to oauth2 authentication which allows facebook, twitter, google
etc authentication

add spring-test and junit
add jetty plugin which allows mvn jetty:run