Changes

This is an attempt to generalize the idea of [http://groups.google.com/group/sugar-network/browse_thread/thread/4cad05ec801f364c user/resource levels] with idea that objects should not be removed from the Network immediately (only hidden, and permanently removed by Network administrators). So, every resource is associated with a layer, i.e., it might be visible for observers only if they requested this layer and have permissions to see it.

This is an attempt to generalize the idea of [http://groups.google.com/group/sugar-network/browse_thread/thread/4cad05ec801f364c user/resource levels] with idea that objects should not be removed from the Network immediately (only hidden, and permanently removed by Network administrators). So, every resource is associated with a layer, i.e., it might be visible for observers only if they requested this layer and have permissions to see it.

For now implemented only the following list of layer but it might be reused for [http://groups.google.com/group/sugar-network/msg/f5a1b4d78494a5d3 teachers related workflows]:

For now, implemented only the following list of layers, but it might be reused for [http://groups.google.com/group/sugar-network/msg/f5a1b4d78494a5d3 teachers related workflows] later:

* {{Code|default}}, the default layer for observers and Network objects; all users can see objects on this layer;

* {{Code|general}}, the default layer for observers and Network objects; all users can see objects on this layer;

* {{Code|deleted}}, Network objects' layer will be changed to {{Code|deleted}} after removing objects by users.

* {{Code|deleted}}, Network objects' layer will be changed to {{Code|deleted}} after removing objects by users.