[1.0.X] Fixed #6767: changed the way the Oracle backend fetches numbers to...

[1.0.X] Fixed #6767: changed the way the Oracle backend fetches numbers to prevent decimals being returned as floats. Backport of [9750] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@9751 bcc190cf-cafb-0310-a4f2-bffc1f526a37