Rename directory and manual files

doc/manual/CMakeLists.txt

doc/manual/dune-fufem.bib

doc/manual/dune-fufem.tex

dune/CMakeLists.txt

dune/fufem-forms/forms.hh

dune/fufem/CMakeLists.txt

dune/fufem/forms/CMakeLists.txt

dune/fufem/forms/baseclass.hh

dune/fufem/forms/boundunaryoperator.hh

dune/fufem/forms/forms.hh

dune/fufem/forms/integrate.hh

dune/fufem/forms/integratedbilinearform.hh

dune/fufem/forms/integratedboundarybilinearform.hh

dune/fufem/forms/integratedboundarylinearform.hh

dune/fufem/forms/integratedlinearform.hh

dune/fufem/forms/localoperators.hh

dune/fufem/forms/localsumassembler.hh

dune/fufem/forms/nullaryoperators.hh

dune/fufem/forms/operators.hh

dune/fufem/forms/productoperator.hh