sf bug [ 1372239 ] Wrong ordering of include files
fixed SF bug 1363610, updated for new aspect ratio handling.
fixed a setup bug for 64 bit systems
fixed a bug in draw_lines
added support for nan's in draw_lines
Added contour.negative_linestyle rcParam
added isnan function to Numeric-flavored numerix
Added _isnan extension module to test for nan with Numeric
rm self._pswriter.write lookups from draw_markers
fixed a bug in draw_markers and draw_lines
