Update setup.py

change install_requires from "orderable" to "django-orderable"
Update setup.py

changed "image-cropping" to "django-image-cropping" in setup.py
fixing doc instruction for THUMBNAIL_PROCESSORS
Included argument for admin site 

Newer versions of django need an admin site argument for instantiation of ForeignKeyRawWidget.
added locale file for pt_BR
Merge pull request #3 from ivancrneto/master

Wrong requirements make pip do not install