Adding Set, SetNode, SetLeaf, SetBisect, Stc, StcEqual
Fixing compilation problems
Set: fix bug diff + add print function
diff (SetNode): fix bugs with espsilon-sized subboxes
Fix bug SetBisect destructor
Creating intersection
Fix bug on the status set to "diff" in SetLeaf::inter
Replace to_vibes by visit_leaves
Renaming files
Cosmetic changes
Add TestSetInterval
Ctc: fix bug check_nb_var_ctc_list + minor fix for CtcInteger
Replacing BoolMask by BitSet (issue #11)
CtcPropag: fix bug on bitsets initialization