merged from master.

dune/alugrid/CMakeLists.txt

+set(SUBDIRS
+  2d
+  3d
+  common
+  impl
+  test)
+
+foreach(i ${SUBDIRS})
+  if(${i} STREQUAL "test")
+    set(opt EXCLUDE_FROM_ALL)
+  endif(${i} STREQUAL "test")
+  add_subdirectory(${i} ${opt})
+  unset(opt)
+endforeach(i ${SUBDIRS})
+
+set(alugrid_HEADERS dgf.hh grid.hh)
+install(FILES ${alugrid_HEADERS}
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/dune/alugrid)