I have briefly reviewed the patch and it looks pretty good.
I notice that username and password items are also now being pulled from the connection string and this appears to be new, but is not mentioned in the ticket.
I've made a few minor other adjustments and prepared a new patch (attached), which I'd appreciate your reviewing and testing.
Also, I can't apply the INGRES.htm as is. Please prepare a patch or new version of drv_ingres.html and do *not* edit it with an HTML editor that will insert lots of cruft.
As these are new features we will incorporate them in trunk. We can discuss backporting to 1.9 once we are happy with the changes in 2.0 if the changes are necessary for 1.9 to function.