Update the Hackerspace status plugin to a more sane information source

At the moment, the status plugin acquires the hackerspace state through polling (an interpreted HTTP request to http://hackerspace.stusta.de). This is unrealiable and dirty. A better way would be a status providing service (e.g. running on knecht), which provides this status over an encrypted/persistent/... channel in a standardized format (e.g. JSON/XML). Once this is implemented, update bernd's status plugin to use this information source.