Moved pure C++ files to cpp subdirectory

setup.py

@@ -390,13 +390,13 @@ setup(
 
       Library("bob.io.image.bob_io_image",
         [
-          "bob/io/image/tiff.cpp",
-          "bob/io/image/gif.cpp",
-          "bob/io/image/png.cpp",
-          "bob/io/image/jpeg.cpp",
-          "bob/io/image/bmp.cpp",
-          "bob/io/image/pnmio.cpp",
-          "bob/io/image/netpbm.cpp",
+          "bob/io/image/cpp/tiff.cpp",
+          "bob/io/image/cpp/gif.cpp",
+          "bob/io/image/cpp/png.cpp",
+          "bob/io/image/cpp/jpeg.cpp",
+          "bob/io/image/cpp/bmp.cpp",
+          "bob/io/image/cpp/pnmio.cpp",
+          "bob/io/image/cpp/netpbm.cpp",
         ],
         packages = packages,
         boost_modules = boost_modules,