[cmake] update to incorporate links to pybind11 files

cmake/modules/CMakeLists.txt

-set(modules "DunePybindxiMacros.cmake")
+set(modules
+    DunePybindxiMacros.cmake
+    DunePybindxiUtils.cmake
+    FindEigen3.cmake
+    FindPythonLibsNew.cmake)
 
 install(FILES ${modules} DESTINATION ${DUNE_INSTALL_MODULEDIR})

dune/pybindxi/CMakeLists.txt

 #install headers
-#install(FILES pybindxi.hh DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/dune/pybindxi)
+install(FILES
+        attr.h
+        cast.h
+        chrono.h
+        common.h
+        complex.h
+        descr.h
+        eigen.h
+        eval.h
+        functional.h
+        numpy.h
+        operators.h
+        pybind11.h
+        pytypes.h
+        stl_bind.h
+        stl.h
+        typeid.h
+        DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/dune/pybindxi)