Major refactoring of Interpreter.
* TODO Still need to factor out the reader
* TODO implement the environment and functions
Implemented function calls and scopish
* TODO implement relational operators, gotofalse, and gototrue
Fixed relational and ! operators
* TODO return values from functions,
  use a separate memory stack for procedures.
Fixed scoping for functions an global
* TODO fix recursion
Added ability to call functions from functions using
dynamic scope(The function being called from another function
has access to the callees variables).
* TODO still need to fix recursion
Major refactoring of Eval
More refactoring
code clean up and last minute attempt to fix recursion.
* TODO fix recursion
added check for source file