AC-FOVE: code refactoring for generalized aggregation parfactors

* AggParfactor: adapted conversion to standard parfactor to work for
generalized aggregation parfactors
* StdPrv: correction in one of the constructors
* Lists: fill() does not clear the list anymore
* AggParfactorTest: test for conversion, multiplication and sum out of
generalized aggregation parfactors. Sum out is not working yet.
AC-FOVE: code refactoring for generalized aggregation parfactors

* Sandbox: moved to br.usp.poli.takiyama.sandbox
* AggParfactor: corrections to sum out on generalized aggregation
parfactor
* AggParfactorTest: test for sum out
AC-FOVE: code refactoring for shatter

* AggParfactor, Parfactor: simplify method
* Shatter: structure for the algorithm (contains compilation errors)
* StdParfactor: simplifier class
* AbstractConstraint: isUnary method
* InequalityConstraint: correction in equals() method
AC-FOVE: code refactoring for shatter

* AggParfactor: simplification for logical variables
* StdParfactor: small adjustments in simplification
* AbstractConstraint, Constraint: logicalVariables() method
* Lists: added builder
* AggParfactorTest: test for aggregation parfactor
* InputOutput: class to abstract mapping for parameterized tests