* Updated StaticFilesHandler and AdminMediaHandler
  to make use of the 404 handler if needed.

* Updated runserver management command to serve static files
  only in DEBUG mode (or if specified the --insecure option)
  and if the staticfiles app is in INSTALLED_APPS. Also added
  an option to disable serving completely (--nostatic).

* Added check in debug mode if STATICFILES_* settings are
  different to MEDIA_* settings.

* Removed a faulty PendingDeprecationWarning in AdminMediaHandler
  that is triggered every time runserver is used.

* Fixed an issue with the modification time checks when
  running collectstatic.

* Extended and refined documentation.

Thanks to everyone for input, especially to Carl Meyer, Ted Kaemming and
Adam Vandenberg for patches.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14533 bcc190cf-cafb-0310-a4f2-bffc1f526a37