Updating guidelines for developers

[John W. Eaton]

On 19-Apr-2011, Rik wrote:

| 4/19/11
| 
| I'm just putting this issue out there.  We probably need to update the
| Contributing Guidelines and the downloads page
| (http://www.gnu.org/software/octave/download.html) to reflect the new
| design methodology with branches.  It might behoove us to do this sooner,
| rather than later, so that we get patches in the easiest format to apply.

Now that I've checked in my changes to generate the ChangeLog file
from commit messages, I'll try to update this in the next day or two.
If anyone has suggestions or would like to help with this, let me
know.

Thanks,

jwe