Remove outdated examples subfolder

examples/dg.ufl

-V = FiniteElement('CG',triangle,2)
-u = TrialFunction(V)
-v = TestFunction(V)
-x,y = SpatialCoordinate(triangle)
-n = FacetNormal(triangle)
-
-d_f = FacetArea(triangle)
-
-alpha = 1.3
-
-rho = as_matrix((
-    (1.0,0.2),
-    (0.2,1.0)
-    ))
-
-#r = (avg(u)*inner(n('+'),jump(grad(v))) + inner(n('+'),jump(rho*grad(u)))*avg(v) + alpha / d_f * jump(u)*jump(v))*dS(0)
-r = (avg(u)*jump(v) + avg(v)*jump(u))*dS
-
-forms = [ r ]

examples/mixed.ufl

-V =  VectorElement("CG", triangle, 1, dim=3)
-u = Coefficient(V)
-v = TestFunction(V)
-
-r = inner(u,v)*dx
-
-forms = [r]

examples/stokes2d.ufl

-cell = triangle
-P2 = VectorElement("Lagrange", cell, 2)
-P1 = FiniteElement("Lagrange", cell, 1)
-TH = P2 * P1
-
-(v, q) = TestFunctions(TH)
-(u, p) = TrialFunctions(TH)
-
-f = Coefficient(P2)
-
-r = (inner(grad(v), grad(u)) - div(v)*p + q*div(u) - dot(v, f))*dx
-
-forms = [r]