Update .gitignore for Eclipse, at least a little bit.
Add code file for merge invariants.
Update the template for problem 1 answers.
Add Makefile for problem 1.
Ignore .DS_Store.
Add code for Problems 2 and 3.
Add Eclipse files for Problems 2 and 3.
Add Eclipse files for Problem 4.
Add a DictionaryFactory that I'm about to remove.
Whoops.  Add Eclipse Classpath.
Ignore vi tmp files.
Add files for open hash tables in problem 4.
Add association lists to problem 4.
Add a size field to association lists (to support chained hash tables).
Correct intro comment in association list tests.
Update OpenHashTable.java to use this.find rather than find.
Add chained hash tables.