[CMake] Fix install paths for lib and aclocal
- Include missing lib as subdirectory to CMake
- Install duneistlam2cmake.lib to CMAKE_INSTALL_LIBDIR instead of MAKE_INSTALL_BINDIR/../lib which is wrong for several Unices which may use lib64 or similar
- Install m4 files to dune/aclocal instead of aclocal, conforming dune-common and the Autotools