[1.2.X] Use Sphinx `:download:` directives for spatial database template...

[1.2.X] Use Sphinx `:download:` directives for spatial database template creation scripts instead of linking to geodjango.org.

Backport of r15854 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15855 bcc190cf-cafb-0310-a4f2-bffc1f526a37