Updating MAXFLOW version to 3.03.

Hello!
I noticed that Vladimir Kolmogorov [updated his maxflow library](http://pub.ist.ac.at/~vnk/software.html), solving a bug, so I'm updating this fork.

P.S. In your documentation there is a broken link to [his homepage](http://www0.cs.ucl.ac.uk/staff/V.Kolmogorov/), that is now changed to [this one](http://pub.ist.ac.at/~vnk/). :)