TODO * change character constants to have a leading array length * pointers to array elements and struct elements * operator precedence * test character array pointers and dereferencing * '->' * make printf() honour memory constraints * interactive mode * casts * enum * pointer arithmetic * fix type comparison to take into account array size * fix return of array types * expression and auto-cast support for all types * change heap to use a single consistent freelist node struct * periodic heap cleanup * octal/hex character constants * fix #include * assignment on declaration Need test/debug: * all break/continue variations * #define Also: * Remove Var parameter from HeapPopStack() once we're certain it all works