AC-FOVE: the algorithm!

* ACFOVE: a first version of the algorithm
* AggParfactor: method to check for elimination feasibility
* CountingConvert, FullExpand, GlobalSumOut, Propositionalize,
Shatter, ShatterOnQuery, ConvertToStdParfactors, ImpossibleOperation:
algorithm's
macro
operations
* StdParfactor: method to check for elimination feasibility,
corrections in counting
* Factor: documentation
* Parfactor: method to check for elimination feasibility
* Tuple: new factory
* CountingFormula: correction in constructor, fix on terms()
* LogicalVariable: documentation
* RandomVariableSet: correction in constructor
* StdLogicalVariable: correction to get individuals satisfying a set
of constraints.
* StdPrv: documentation
* Lists: replace method, correction in hashCode
* ACFOVETest: tests for AC-FOVE algorithm, including also tests for
C-FOVE
* MacroOperationTest: added old tests (need to correct some results)
* StdParfactorTest: new test for logical variable simplification
* InputOutput: now allows multiple outputs
* ParfactorDecorator, Scanner: decorator pattern to make a deep scan
on logical variables
* MutableQueueTest: tests for mutable queue, a special queue created
for Shattering

The algorithm is in a quite raw state, tested for some specific cases.
AggregationParfactors are used only for initialization.