Modify getReductibleElements & reduction.

Modify ClosureSystem.getReductibleElements method (please read carefully to look for errors :-)
Modify ImplicationalSystem.reduction method (please read carrefully to look for errors :-)
Made BijectiveComponentTest Windows compliant
Complete tests for ImplicationalSystem
Begin test for ClosureSystem
Update ChangeLog
Merge https://github.com/kbertet/java-lattices

Conflicts:
	ChangeLog
Update ImplicationalSystem.iuml file
Update ChangeLog
Add missing tests to ClosureSystem
	* there is a strange behaviour on some tests
Add random method in Context.java
	* Update Context.iuml
	* Add test
Update ChangeLog
Add LatticeFactory class which generates :
	+ random lattices (by an ugly code)
	+ cartesian product of two lattices
	+ lattice of permutations
	+ boolean algebras

Consequently add :
	+ Permutation class for ... lattice of permutations
	+ Couple class for lattice product

For each of these three classes :
	+ Add iuml file
	+ Add unitary tests

Don't forget to update ChangeLog :-)
Merge https://github.com/kbertet/java-lattices

Conflicts:
	ChangeLog
Add unit tests for Lattice class.
Merge https://github.com/kbertet/java-lattices

Conflicts:
	ChangeLog
Merge pull request #60 from JeanFrancoisViaud/master

Modify getReductibleElements & reduction