There seems to be an inconsistant behaviour when the mouse hovers over the icons
in the tree view... (not the branch icons, but the object icons)

- icons on branches with children give a hover effect exactly like that of the
names.

- icons on branches that have no children do not have the hover effect... but
the names still do.

either remove the behaviour on all brannch icons or add the behaviour to the
childless branch icons.