Update TODO list

[[Imported from SVN: r5922]]

TODO

@@ -23,10 +23,10 @@ without any again.
   Once for computing the residual, once for finding the diagonal entry.
   This could be done in one loop.
 * The ProjectedBlockGSStep 'solves' the local obstacle problems
-  by a local projected GS with a fixed number of 20 iteration steps.
-  For scalar valued problems one would be enough. Even for vector valued
-  problems one might still be OK but much cheaper. (Does this have any
-  performance impact on linear elasticity problems?)
+  by a local projected GS with a fixed number of 20 iteration steps
+  for blocksize!=1. Even in this case using only one step might still
+  be OK but much cheaper. (Does this have any performance impact on
+  linear elasticity problems?)
 
 
 
@@ -75,6 +75,5 @@ A wish list for features that would be very welcome.
 * Transfer operator assembler for adaptively refined grids (without refinementtype=copy)
   This is already implemented in dune-fufem. It could be moved here if the
   dependency on P1NodalBasis is removed.
-* Nested iteration for ObstacleTNNMGStep.
 * An interface to add custom output and termination criteria to the LoopSolver.