AC-FOVE: code refactoring for Counting Formula

* Added more methods to counting formulas
AC-FOVE: Code Refactoring for ParameterizedFactor

* New methods in MathUtils: multinomial, factorial, combination and
pow
* Set utilities applied to Lists
* Refactoring of ParameterizedFactor, which now is only Factor. Old
code kept for compatibility.
* Inefficient methods were remade, such as sum out for counting
formulas
* Factor is now back to BigDecimal values (taken out previously due to
the absence of pow method for fraction exponents)
* Deprecation: IntTuple, OldCountingFormula,
ParameterizedRandomVariable, PredicateSymbol, ParameterizedFactor