Level #1 - convert the histogram code to:

    Produce the histogram.
    Design & implement a Huffman binary tree package to:
        Create tree nodes from a letter, count, and left & right siblings.
    Design & implement a sorted list package supporting:
        The insertion of tree nodes sorted by their count.
        Determining the size of the current list.
        Removing and returning the tree node at the list head (the
            tree node with the smallest count).
    Create the initial sorted list from the huffman counts:
        Generate 26 initial tree nodes for each letter & count with NULL children links.
        Insert each of these nodes in the sorted list.

Initial estimate = 8
Actual time = 14



