54146059 about objects master

- Everything is an object, even classes, numbers and nil.
- All objects have a to_s method that converts them to a string representation of that object.
- Every object has an inspect method, which may or may not produce the same output as the to_s method, and is
  generally closer to what appears in code.
- All objects have an object id, which is of the Fixnum class.
- Each object has a different object id.
- The object IDs of small integers follow the pattern n * 2 + 1.
- Using Object.clone creates a clone with a new object ID.
[#54146059]