Implement Class

[idenning2003]

Class should be a private constant struct with these function pointers:

• name() -> const char*
• repr(const void) -> rope_t
• hash(const void*) -> uint64_t
• cmp(const void, const void) -> int

For every instance of classes such as Integer, List, Tree, etc. all functions will have to be tied into an instance of class_t.