Added sites to the readme.
Added Thejaswi Puthraya to AUTHORS.
Fix some static urls in admin to support external storage backends.
Bump grappelli/filebrowser versions.
Version bump to 1.4.5
Added tag 1.4.5 for changeset d71ab836ca8d
Update auto generated CHANGELOG, requirements.
Fix set_dynamic_settings for projects without AUTHENTICATION_BACKENDS defined.