[Ipopt] New release 3.6.0

[Andreas Waechter]

Hi,

I just created a new release (3.6.0) of Ipopt.  The changes include:

- A new version of the Matlab interface (thanks to Peter Carbonetto).  The
   interface is simplified, and the configure script is detecting the
   matlab installation.

- A new option to set CPU time limit (max_cpu_time).

- A ThirdParty/Metis directory to include the matrix ordering package
   Metis.  The linear solvers MUMPS and MA57 perform better with Metis.
   And just as a reminder:  For good performance, those linear solvers also
   require an optimized version of the BLAS libraries (the provided
   ThirdParty/Blas directory gives you only an inefficient but easy to
   install version).

- An update to the CUTEr interface.

- Some files in Ipopt/tutorial for a tutorial paper that I recently wrote
   for a conference.  The tutorial should be available soon as IBM report
   and I will then add a link at the Ipopt Trac page.

Andreas