Fixes #11025 -- ability to specify LOGIN_URL as full qualified absolute URL.

auth.views.login now allows for login redirections for different schemes
with the same host (or no host even, e.g. 'https:///login/')

auth.decorators.login_required can now use lazy urls (refs #5925)

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14733 bcc190cf-cafb-0310-a4f2-bffc1f526a37