Revision 1801736

Fixed some annoyances and abbeyances:

- log information to the log service in case a generic action like "store" or
  "revert" fails;
- in case a login fails due to problems with the backend, do not show the main
  grid (causing multiple grids to appear when trying to login again);
- show more information about the state changes of a target in the status line
  (instead of `Target foo null` message).