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/Perlin2D.cpp

@@ -17,7 +17,7 @@ NzPerlin2D::NzPerlin2D()
             gradient2[i][j] = grad2Temp[i][j];
 }
 
-NzPerlin2D::NzPerlin2D(int seed) : NzPerlin2D()
+NzPerlin2D::NzPerlin2D(unsigned int seed) : NzPerlin2D()
 {
     this->SetNewSeed(seed);
     this->ShufflePermutationTable();