21.12.2014
  commit for the safety refactoring.
22.12.2014
  a big refactoring
  - removed: 'number' data type
  + added: 'float' and 'int' data types

  - removed: TypeCast class
  + added: type casting is a business of the Value class now
  + changed: Value class fields now are private.

  + changed: The RegisterPool class was renamed to ValuePool.
    And it stores the Value objects now.

  + number of changes.