** Post-processing: Huge cleaning

 -- Using PView
 -- Removing Writer for FEMSolution and ElementSolution (layer for PView)
 -- Adapting System
 -- Interpolator simplified (left until PView can handel arbitrary basis)

** Mesh: new method
 -- Can access all the coordinates of the vertices
 -- Used by Interpolator

** Simulations: Huge Cleaning
 -- Intializing by SmallFem for all simulations
 -- Merging all Projections into on code
 -- Use of FEMSolutions and ElementSolutions
 -- Rewriting ShowFunctionSpace to use only FEMSolution
 -- Convergence Tests done again (see further)

** Assembler: Removing SystemShowFunctionSpace
 -- Done in Simulation

** FunctionSpace:
 -- Changing interface in BasisLagrange
 -- Cyclic permutations reactivated in ReferenceSpace (see further)

** WARNING: Without cyclic permutation TetEdgeBasis does NOT converge !!
 -- Works in 2D
 -- Works with TetNodalBasis
 -- Fails with TetEdgeBasis
 -- ShowFunctionSpace shows weird thing for some Tets
 -- Implementation or math error ????

** Convergence Tests WITH cyclic permutation
 -- Works everywhere (line, tri, quad, tet)