added client side heartbeat messages
minor changes

- repositories removed from owner server
- bugfix regarding missing remoteConnectionURI in linkeddata of connection
added  user and needuri specific websocket session handling
Merge branch 'feat-privatelink' into merge-privatlink
Merge branch 'merge-privatlink' into devel

Conflicts:
	webofneeds/won-owner-webapp/src/main/webapp/app/main/main.js
	webofneeds/won-owner-webapp/src/main/webapp/app/service/user-service.js
merged