Sync from devel:
    Fri Jan 29 2010 Kevin Kofler <Kevin@tigcc.ticalc.org> - 2.5-9
    - also remove include/agg_conv_gpc.h as it also carries a copy of the
        non-Free GPC license (upstream also recommends removing that file under
        http://www.antigrain.com/license/index.html#toc0005) (#559611)