BoolStuff is a small C++ library that supports a few operations on
boolean expression binary trees. The main features are: 
- a boolean expression parser (supports operators AND, OR
  and NOT, as well as parentheses);
- an algorithm to convert a boolean expression binary tree
  into its Disjunctive Normal Form;
- a function that determines if an expression tree is in DNF.
A command named `booldnf' that calls this library is also provided.
