Similar to the dir.property model, ir.attachments may have arbitrary
properties, too. Note that we hide them from normal users, only list
them in separate form (don't want to bloat the ir.attachment one, even
at the XML level).
bzr revid: p_christ@hol.gr-20101207133955-8n6ipccdnygnuncn
The 'node_res_obj' has been the right class to use for the intermediate
nodes, ever since. The assertion that it should only apply to static
dirs was wrong.
bzr revid: p_christ@hol.gr-20101027102323-qewjjzzudj0zz643
P. Christeas