find .pxd include directories automatically during installation

setup.py

@@ -37,32 +37,35 @@ if sys.version_info[0] >= 3:
     build_py.fixer_names = fixers
     add_command_class("build_py", build_py)
 
-pxd_packages = ['cpython', 'libc', 'libcpp']
+pxd_include_dirs = [
+    directory for directory, dirs, files in os.walk('Cython/Includes')
+    if '__init__.pyx' in files or '__init__.pxd' in files
+    or directory == 'Cython/Includes' ]
+
+pxd_include_patterns = [
+    p+'/*.pxd' for p in pxd_include_dirs ] + [
+    p+'/*.pyx' for p in pxd_include_dirs ]
 
 if sys.version_info < (2,4):
     install_base_dir = get_python_lib(prefix='')
     import glob
-    patterns = ['Cython/Includes/*.pxd',
-                'Cython/Plex/*.pxd',
-                'Cython/Compiler/*.pxd',
-                'Cython/Runtime/*.pyx']
-    for p in pxd_packages:
-        patterns.append('Cython/Includes/%s/*.pxd' % p)
-        patterns.append('Cython/Includes/%s/__init__.pyx' % p)
+    patterns = pxd_include_patterns + [
+        'Cython/Plex/*.pxd',
+        'Cython/Compiler/*.pxd',
+        'Cython/Runtime/*.pyx'
+        ]
     setup_args['data_files'] = [
         (os.path.dirname(os.path.join(install_base_dir, pattern)),
          [ f for f in glob.glob(pattern) ])
         for pattern in patterns
         ]
 else:
-    patterns = ['Includes/*.pxd',
-                'Plex/*.pxd',
-                'Compiler/*.pxd',
-                'Runtime/*.pyx']
-    for p in pxd_packages:
-        patterns.append('Includes/%s/*.pxd' % p)
-        patterns.append('Includes/%s/__init__.pyx' % p)
-    setup_args['package_data'] = {'Cython' : patterns}
+    setup_args['package_data'] = {
+        'Cython.Plex'     : ['*.pxd'],
+        'Cython.Compiler' : ['*.pxd'],
+        'Cython.Runtime'  : ['*.pyx', '*.pxd'],
+        'Cython'          : [ p[7:] for p in pxd_include_patterns ],
+        }
 
 # This dict is used for passing extra arguments that are setuptools 
 # specific to setup