Support Django 1.5.

- Fixed adminmedia, admin_media_prefiix
- Remove simple, redirect_to and defaults modules which are deprecated in
  Django 1.5. And replace 'redirect_to' with RedirectView.
Add CLOUD_BROWSER_CACHE_SECONDS to settings.
Add two generic exception: StorageResponseException and ClientException.

to catch server side error response (http status code), and client side
exception, like non-standard container name.
Add new features to django_cloud_browser AWS S3.

- Upload a file.
- Create a new directory.
- Delete a file or a directory.
- Rename a file or a directory.
- Move a file to another directory.

cloud/base.py
    - Add generic methods to base.py.

cloud/boto_base.py, cloud/aws.py
    - Realize generic methods for AWS under cloud/boto_base.py, and upload form
      under cloud/aws.py.

views.py
    - Add upload, mkdir, delete, rename, and move views. (Some code might be still
      specific for S3, need to improve it.)
    - Support different backend datastores upload html forms.

common.py.
    - Modify path_join(), so that with inputs 'foo/', 'bar', it will return 'foo/bar',
      not 'foo//bar'.
    - Add path_join_sep(), which returns a path ends with '/', we can use this
      method to get directory path (maybe specific for s3 only).

Templates:
    - Add rename, move template files.
    - Improve template file _browser.html.
        - Add upload, mkdir, delete, rename, move html forms.
        - Insert 3 columns (Delete, Rename, Move to).

Icons:
    - Use the tango project icons for mkdir/delete/rename/move.

Admin site:
    - Add rename, move block div to admin/base.html.
    - Add rename and move admin template files, which are with admin/base.html.
    - Add the file operations urls to admin site.
Add the file opeartions for file system.
Add fab test and include it in fab check.
Add logging to the project.
Remove manage.py under cloud_browser_project.

- Because when deploying filer on heroku, this manage.py also will be called
  resulting deploying failure.
Pylint disable.
Not show report when running fab pylint, remove this commit later.