change Teacher's property serviceHours to adminHours
add service hours computation for teachers
show service hours instead of admin hours in AdminStatusPanel
change: scrollpane for tree is now in MainFrame not in SchedulesTree
add listener to tree
change class based display delegation renderers pattern

presenter now owns a CBDDR and uses a DefaultMutableTreeNode UserObject ClassBased DDRR to unpack path components from TreeNodes
tree uses a ClassBased TreeCell DDR which is created with a CMTN UO CB DDR which is created with the presenter's simple CBDDR
modify ScheduleStatusPanel to use only one modifiable label
add: modify ScheduleStatusPanel's label according to the tree selection
remove plural from tree root's direct child