Added eval to block ast node -- this was for the creation of definitions
Changed the signature of Eval to return a 'Value' as opposed to a dynamice interface type
Since Heap is its own structure now, the heap count had to be accessed differently
Implemented ast.Define's Eval method
Added an interface for Ident with a Name() method, and implemented both on Global and Local variables
Since we changed the name of Ident to Local for the AST node, we need to changed the parser
Added the NewObject method to create new objects
GenID has been decoupled from the Runtime, and now reserves the ID created in Heap.
Added Heap as its own structure, and added the appropriate functions for insertion and lookup