change the way mixins are being added by setup.py, may fix #79

setup.py

@@ -9,7 +9,7 @@ readme = open('README.rst').read()
 
 
 setup(name='jedi',
-      version='0.5b4',
+      version='0.5b5',
       description='An autocompletion tool for Python that can be used for text editors.',
       author=__AUTHOR__,
       author_email=__AUTHOR_EMAIL__,
@@ -19,7 +19,8 @@ setup(name='jedi',
       license='LGPLv3',
       keywords='python completion refactoring vim',
       long_description=readme,
-      packages=['jedi', 'jedi.mixin'],
+      packages=['jedi'],
+      data_files={'jedi': ['mixin/*.py']},
       platforms=['any'],
       classifiers=[
           'Development Status :: 4 - Beta',