[1.2.X] Fixed #8567 -- Clarified the process of instantiating FormWizards....

[1.2.X] Fixed #8567 -- Clarified the process of instantiating FormWizards. Thanks to ClaesBas for the suggestion, and ElliotM and timo for draft text.

Backport of r13543 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13545 bcc190cf-cafb-0310-a4f2-bffc1f526a37