Implement SKIP_PDL_CHECK option for the case where the libplplotd soversion required by PDL-Graphics-PLplot is not (yet) installed.
Implement SKIP_PDL_CHECK option for the case where the
libplplotd soversion required by PDL-Graphics-PLplot is not (yet)
installed.

svn path=/trunk/; revision=11261

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot