Implement dune-functions compatible Laplace assembler
requested to merge patrick.jaap_at_tu-dresden.de/dune-fufem:feature/functions-laplaceassember into master
The old implementation was only compatible with fufem-bases.
The assembler is more or less a copy of the localMassAssembler and the test is integrated into the mass assembler test, which is renamed to localassemblertest.