Add base value support to bars

[Michael Goffioul]

On 12/18/07, Michael Goffioul <michael.goffioul at gmail.com> wrote:
> The following patch adds support for a base value in bar functions. Note
> that I'm not sure about the expected behavior in case of stacked bars, as
> I don't have Matlab under the hand to check it.

Oops, I forgot a changelog.

scripts/ChangeLog:

2007-12-18  Michael Goffioul <michael.goffioul at gmail.com>

    * plot/__bar__.m plot/__bars__.m: add support for base value