Partly completed code for "playground mode", issue #52
Committing Andrei's code from his thesis to the Analysis project.
Incomplete code for rewriting code to perform tracing.  Lots of work
left to do:

* random inner blocks
* inheritance hierarchy for MyStatement class? (currently uses an enum
to track the type, which isn't very OO)
* loop counts and nested loop counters
* re-write vardecs with default value assignments, i.e. String str;
should be String str=null;
* re-write return statements
* don't instrument break or throw, at least for now
* not sure what to do with catch statements; ignore for now
* wrote this on my whiteboard: "vars created after start line of stmt
(for loop?) if even possible..."  Unsure what this means