make the shadow optional

[Google Code Exporter]

It would be useful in some cases that the shadow is optional and not mandatory 
as presently.

For that purpose I attach a patch so that the user gets an option to disable 
the shadow.

Original issue reported on code.google.com by [e-mail] on 28 Feb 2011 at 1:58

Attachments:

• wheel-optional-shadow.diff