sensor lifetime defaults to forever


git-svn-id: https://gnunet.org/svn/gnunet@33928 140774ce-b5e7-0310-ab8b-a85725594a96
new sensors + disabled reporting by default


git-svn-id: https://gnunet.org/svn/gnunet@33929 140774ce-b5e7-0310-ab8b-a85725594a96