Added notion of ‘subnode’: a particular note by a particular user. subnodes agregate up to ‘nodes’: nodes are the set of all subnodes about a given entity (by default, subnodes with the same title).
Added users page.
Nodes page now lists the size of the node (number of subnodes).
Added subnode-viewing mode, in which you can see just notes (files actually) by a particular user (and link to them).