Add base value support to bars

[John W. Eaton]

On 19-Dec-2007, Michael Goffioul wrote:

| On 12/19/07, Michael Goffioul <michael.goffioul at gmail.com> wrote:
| > > When you send patches directly in your messages, they often arrive
| > > with long lines wrapped.  Can you send them as text/plain attachments
| > > to avoid that?
| >
| > OK.
| 
| Here's the patch, in attachment this time.

I applied it and checked it in.

Thanks,

jwe