Minor fixes

*Seed is uint instead of int
*Permutation table is uint instead of int, could lead before to program
crash with negative seeds


Former-commit-id: 49ad04987a09a5f5b4bcab6ee3916db9818172b6

src/Nazara/Noise/Simplex2D.cpp

@@ -20,7 +20,7 @@ NzSimplex2D::NzSimplex2D()
     UnskewCoeff2D  = (3.0-sqrt(3.0))/6.;
 }
 
-NzSimplex2D::NzSimplex2D(int seed) : NzSimplex2D()
+NzSimplex2D::NzSimplex2D(unsigned int seed) : NzSimplex2D()
 {
     this->SetNewSeed(seed);
     this->ShufflePermutationTable();