C-FOVE: Shatter

* MacroOperations: added the shattering macro-operation
* SimpleParfactor: changes in debug messages and corrected the unify
method to restore the names of the logical variables after unification
* Parfactor: added method to restore logical variable names
* Parfactors: added method to restore logical variable names
* LogicalVariableNameGenerator: added method to restore logical
variable names
* MacroOperationsTest and Pool: JUnit test of the shattering
macro-operation.

Implementation of Shatter macro-operation. Tested using the example
provided by Kisysnki (2010).