Refs #17171 -- Updated tutorial sections 3 and 4 to follow the startproject...

Refs #17171 -- Updated tutorial sections 3 and 4 to follow the startproject template and consistently use url() function in URLconf. Thanks haimunt for the report.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@17073 bcc190cf-cafb-0310-a4f2-bffc1f526a37