[Ipopt] Ipopt maintenance release 3.12.9

[Stefan Vigerske]

Hi,

I just created a new Ipopt maintenance release.
If you were using a recent Ipopt version successfully, then there is no 
need to update. However, note that the handling of the time limit 
changed when reoptimizing.

Here is a list of changes:
- fixed memory leak in MA86 interface (by mhahn) [r2700,#283]
- fixed handling of time limit when reoptimizing: CPU time spend
   was accumulated when reoptimizing, while it should have been
   reset for each solve (by paul-scott) [r2702,r2703]
- fixed sign in Jacobian finite-difference approximation when point
   was close to variable upper bounds (by Enrico Bertolazzi) [r2704]

The source tarballs should be available tomorrow.

Enjoy,
Stefan