HierarchyTreeNode: Swapped one mode for two. 
- The new enum modes are 'activeMode' and 'selectedMode'.
- Setup new setter/getter methods.
MyController: Reflect changes in HierarchyTreeNode.
- Renamed 'updateNodes' to 'updateChildNodes', matching the existing
'updateParentNodes' method. 
- Update the 'updateChildNodes' method to use the new 'ActiveMode' and
'SelectedMode' in HierarchyTreeNode.  
- Update 'updateChildNodes' to use a different method signature, test
the nodes for 'active' or 'selected' rather than directly setting the
mode.
MyTreeRenderer: Update to reflect HierarchyTreeNode. 
- Rendering based on the active mode, and selected mode of each node. 
- Moved setting the font into the 'selected' switch.
MyController: Implement the 'updateParentNodes' method.
MyTreeRenderer: Add support for partial selected/active nodes. 
- Remove debugging print to screen messages. 
- Tweaked the 'orangeColor'.
MyStatusBar: Initial commit.
MyController/MyView: Add in a status bar.