When opening something in the left-side treeview, it also opens in the
right-side directory view. That triggers the "path changed" hook in the
directory view, which causes us to fully reveal the opened directory
in the left-side treeview.
This feedback loop made the UI feel weird since it caused directories
to expand just by selecting them in the left-side treeview. So let's
break that loop.
e1965a5a8e