WIP add basic cut and paste to archival objects in a resource tree
Add an endpoint to allow bulk move of AO's to either a resource or another AO... plus some tweaks to the JS tree to allow multiselecting of nodes
Allow multiple nodes to be cut, pasted or moved to the resource node or any children
Add multiselect and cut/paste to the digital object tree view
Remove commented code from tree.js
Clean up code based on review; Also apply cut/paste/multiselect changes to the classificaiton tree form/endpoints;  removed the '/parent' endpoint from the frontend as 'accept_children' replaces this;
Fix bug where a newly created node cannot be moved as it doesn't know it's own uri
add event types for accessions
remove redundant event types
replace 'cataloging' with 'cataloged' in the event model
Split node query building into separate method
Pull out title generation
Push record-specific code down into lower-level mixins
WIP on classifications in public interface
Clean up the tree schemas and remove the unused accession_tree (and its endpoints)