Log Message:
GLPK 4.52.1 (release date: Jul 28, 2013)

        This is a bug-fix release.

        A version information bug in Makefile.am was fixed. Thanks to
        Sebastien Villemot <sebastien@debian.org> for bug report.

GLPK 4.52 (release date: Jul 18, 2013)

        The clique cut generator was essentially reimplemented, and now
        it is able to process very large and/or dense conflict graphs.

        A simple rounding heuristic was added to the MIP optimizer.

        Some bugs were fixed in the proximity search heuristic routine.
        Thanks to Giorgio Sartor <0gioker0@gmail.com>.

        New command-line option '--proxy [nnn]' was added to glpsol to
        enable using the proximity search heuristic.

        A bug (incorrect processing of LI column indicator) was fixed
        in the mps format reading routine. Thanks to Charles Brixko for
        bug report.