==== Flock Viewer/Editor ====

  * View mode: shows the name of the Flock and lists the Flockrs in the Flock.
  * Edit mode: shows the name of the Flock and lists the Proximities from which it is defined. The different Proximities are chained together with operators which can also be changed (and, or, not...).
  * There is an add button to add a new Proximity with its corresponding operator, and there is a remove button to remove a Proximity from the list.