US1 - As an international accountant I need a simple RPN adding machine
so that I can easily manage my clients books.

1: All values and operators are delimited by whitespace.
2: Accepts a continuous stream of values and operators.
3: Supports operations for sum, difference, division, multiplication.
4: Supports floating point operations.
5: Console input processed after every 'enter' key-press.
6: When an operator is read
- Output the list of all remaining values entered followed by the operator
- Perform the operation
- Display the resulting list of values awaiting further operators.