WL-2366 create jstree oxford theme
WL-2366 change indentation and height
WL-2366 add listener for open_node
WL-2366 close any other open nodes
WL-2366 finish comment
Move the accordion into a separate plugin.
WL-2366 fix merge conflict
Merge remote-tracking branch 'origin/WL-2366' into WL-2366
WL-2366 add back boxes
WL-2366 Give boxes full borders and margin.

This means they look like nested boxes rather than trying to make them like a table.
Merge branch 'WL-2366'