[1.0.X] Fixed #11374 -- Modified the documentation for forms.BooleanField to...

[1.0.X] Fixed #11374 -- Modified the documentation for forms.BooleanField to allow for the fact that it can be rendered using widgets other than a checkbox. Thanks to lygaret for the patch.

Merge of r11236 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@11243 bcc190cf-cafb-0310-a4f2-bffc1f526a37