[Ipopt] Ipopt releases 3.11.11, 3.12.2, and 3.12.3

[Stefan Vigerske]

Hi,

I just created a new Ipopt maintenance releases.
If you were using MA97, it is suggested to update.

Here is a list of changes for 3.12.3 and 3.11.11:
- fixed bug in MA97 interface that lead to conversion issues
   (by J. Hogg) [r2566, #260]

Previously, we had a 3.12.2 release with the following change:
- revised integration of doxygen documentation into build system
   (by Ted Ralphs)

The source tarballs should be available tomorrow.

Enjoy,
Stefan