Monkey patch s3boto storage to properly quote file names.
This is a temporary solution until:
* django-storages issue #172 is fixed (http://code.larlet.fr/django-storages/issue/172/storageurl-should-quote-file-names-before#comment-4149177)
OR
* pull req #70 is merged (http://code.larlet.fr/django-storages/issue/172/storageurl-should-quote-file-names-before#comment-4149177)
Merge pull request #5 from pbs/special_url_chars_on_s3

Monkey patch s3boto storage to properly quote file names.