Make 'dune' a real directory instead of a symlink, and move subdirectory

'ag-common' to dune/fufem.

[[Imported from SVN: r3520]]

configure.ac

@@ -9,9 +9,6 @@ AM_CONFIG_HEADER([config.h])
 # check all dune-module stuff
 DUNE_CHECK_ALL
 
-# The infamous dune --> . symlink.
-DUNE_SYMLINK
-
 # preset variable to path such that #include <dune/...> works
 AC_SUBST([AM_CPPFLAGS], '$(DUNE_CPPFLAGS) -I$(top_srcdir)')
 AC_SUBST([AM_LDFLAGS], '$(DUNE_LDFLAGS) $(DUNE_LIBS)')