Improve move value function of array tree

The moveValue function of array trees now allows to move values between
arrays outside of the array tree.
Merge branch 'master' of https://github.com/OpenDSA/OpenDSA
Modify exmple to show bug

Replicated bug when positioning nodes in a tree. It appears that hidden
nodes affect the layout of the tree.
Add strong edge highlight style
Finish second slide show

Completed slide show for promote insert and started on slide show for
root split insert.
Merge branch 'master' of https://github.com/OpenDSA/OpenDSA