[la.containerfactory] revamp
follow the structure of la.solver in dune-stuff
[autotools] update
[assembler.gridwalker] added first draft
seems to work
[operator.interfaces] added first draft for product interfaces
[operator.products] updated L2
[tests.operators]
* added tests for several products
* disabled other tests for the moment
[operator.products] fixed L2Generic
[operator.interfaces] added OperatorInterface
[operator.projections] derived from interface
[test.operators] major update
* added test for assemblable products
* reenabled test for generic product
* reenabled tests for projection operators
[operator.interfaces] apply source/range in correct order
[operator.products] updated H2Semi to new interfaces
[tests.operators] reenabled H1Semi tests for all variants
[dune.module] suggest dune-pdelab
[cmake] added dune-typetree and dune-pdelab
[basefunctionset.pdelab] added first draft
[mapper.pdelab] added first draft
[space.continuouslagrange.pdelab] added first draft
[mapper.fem] fixed guard
[space.continuouslagrange] added missing resize in operator=