Count them words

Goal: Find the 20 most common words in our wondrous textbook.

1. Type in the code from the book that uses the built-in Hashtable to count word frequencies.
2. Download the text of the book from

   http://rocky.wellesley.edu/cs230/code/hw10/text.txt

3. Think about how to handle punctuation and any other wierdness that appears in the file.
4. How many different words are there?
5. Think about how to find the 20 most common. Hint: is there another data structure that might help?