1. We were incorrectly ignoring the input (key, value) when inserting into an empty node.
2. Insertion into empty tree is supposed to start out as a red node, not a black one.
3. Fix bug in the size() routine.
4. Some method renaming.
5. Implemented the graphing code so we can visualize what is going on.
6. Implement the empty() and singleton() static factory methods.
7. The renaming of fields in Netbeans is broken.  Fix the fallout.