* Move value specific Iterable and Iterator interfaces into core module
* Update Makefile
Reverted test command
* Update collection.go
* Fixed wrong iterator usage
* Updated use of switch statements
* rename method Clone to Copy
* added Cloneable interface
* added Value to Cloneable interface
* implemented Cloneable intefrace by array
* implemented Cloneable interface by Object
* unit tests for Object.Clone
* move core.IsCloneable to value.go
* change Clone function
* move IsClonable to package values