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Summary of new developments in Google or-tools

Laurent Perron wrote the following summary of the developments in Google or-tools:
Here is what we have been doing in Q3.

Graph algorithms:
- a lot of work went into making the algorithms (min cost flow, max flow) incremental after small modifications.

Linear solver:
- Added utility of constraints, primal and dual tolerances.
- Basis status of variables.
- Added solving model from protobuf, outputting solutions as protobuf. Useful for having MP solvers in another process or machine for instance.

Constraint solver:
- Added complete model visitor
- Applications to pretty print the model or display special stats
- Main application is to implement model read/write to file. I will send another message to detail all this.
- Added model_util binary to query/test/modify exported models.
- Change the internal way of storing constraints and expressions in caches to avoid duplicating equivalent classes.
- Lots of cleanup for the reference manual. Size has been divided by nearly 4 by hiding all implementation classes: check http://or-tools.googlecode.com/svn/doc/full_reference_manual/or-tools/index.html

And of course the usual batch of bug fixes.

--Laurent (on behalf of the complete Operations Research team at Google).