TODO

Bugs:
* int fact(int i) {
   if (i < 2) {
       return i;
   }
   return (i * fact(i - 1));
}
* something wrong with interactive mode after error handling - not clearing token buffer correctly?
* parsing of statements not quite right - seems to optionally want extra tokens at end

Implement:
* operator precedence
* pointer arithmetic
* casts
* char access/char array access/char * access

Improvements:
* #define with arguments
* pointers to array elements and struct elements
* test character array pointers and dereferencing
* make printf() honour memory constraints
* 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
* see if we can use ParserCopyPos() in other places rather than copying everything

Need test/debug:
* all break/continue variations

Also:
* Remove Var parameter from HeapPopStack() once we're certain it all works