add supra test cas

Solver/TESTCASES/square_supra.geo

+Point(1) = {0.0, 0.0, 0, .03};
+Point(2) = {1, 0.0, 0, .03};
+Point(3) = {1, 1, 0, .03};
+Point(4) = {0, 1, 0, .03};
+Line(1) = {4, 3};
+Line(2) = {3, 2};
+Line(3) = {2, 1};
+Line(4) = {1, 4};
+Line Loop(5) = {2, 3, 4, 1};
+Plane Surface(6) = {5};
+Physical Line("Top") = {1};
+Physical Line("Right") = {2};
+Physical Line("Bottom") = {3};
+Physical Line("Left") = {4};
+Physical Surface("Inside") = {6};
+//Transfinite Line {1, 2, 4, 3} = 2 Using Progression 1;
+//Transfinite Surface {6};

Solver/TESTCASES/supra.lua

+model = GModel  ()
+model:load ('square_supra.geo')
+model:load ('square_supra.msh')
+dg = dgSystemOfEquations (model)
+dg:setOrder(1)
+
+
+function diffusivity( sol , f )
+  n=20
+  c=1e-3
+  for i=0,sol:size1()-1 do
+    f:set (i, 0, sol:get(i,0)^(n-1)*n/c )
+  end
+end
+
+law = dgConservationLawAdvectionDiffusion('',functionLua(1,'diffusivity',{'Solution'}):getName())
+dg:setConservationLaw(law)
+
+-- boundary condition
+outsideLeft=fullMatrix(1,1)
+outsideLeft:set(0,0,-1)
+outsideRight=fullMatrix(1,1)
+outsideRight:set(0,0,1)
+law:addBoundaryCondition('Top',law:new0FluxBoundary())
+law:addBoundaryCondition('Bottom',law:new0FluxBoundary())
+leftFunction=functionConstant(outsideLeft):getName()
+rightFunction=functionConstant(outsideRight):getName()
+print(leftFunction)
+print(rightFunction)
+law:addBoundaryCondition('Left',law:newOutsideValueBoundary(leftFunction))
+law:addBoundaryCondition('Right',law:newOutsideValueBoundary(rightFunction))
+
+dg:setup()
+
+-- initial condition
+function initial_condition( xyz , f )
+  for i=0,xyz:size1()-1 do
+    x = xyz:get(i,0)
+    y = xyz:get(i,1)
+    z = xyz:get(i,2)
+    f:set (i, 0,0*math.exp(-100*((x-0.2)^2 +(y-0.3)^2)))
+  end
+end
+dg:L2Projection(functionLua(1,'initial_condition',{'XYZ'}):getName())
+
+dg:exportSolution('output/Diffusion_00000')
+
+-- main loop
+for i=1,150000 do
+  norm = dg:RK44_limiter(0.000005)
+  if (i % 100 == 0) then 
+    print('iter',i,norm)
+    dg:exportSolution(string.format("output/Diffusion-%05d", i)) 
+  end
+end