Doc update
SetLeaf: code optim in inter
iset : add union + minor optim for inter
ExprDiff: add conversion to constants for multi-valued functions
ExprDiff: new test
ExprDiff: allow array of ExprNode instead of symbols
Optimizer: Fix bug (issue #44)
Optimizer: Fix new problem introduced when fixing issue #44 in last commit. Now this issue should be resolved.
Optimizer: Removing message
- correct bug in CtcQuantif (the assert was wrong)
- Correct the feasibility test in OptimCtc
CellHeapOptim : just to have a save of what I try...
CellHeapOptim: remove the previous commit
Merge remote-tracking branch 'origin/OptiContractor'
Merge remote-tracking branch 'origin/master' into OptiCtc_Test

Conflicts:
	src/contractor/ibex_CtcQuantif.cpp
ex_avion : minor change