Proper handling of INSTALL_RPATH for case when ENABLE_DYNDRIVERS OFF.
Proper handling of INSTALL_RPATH for case when ENABLE_DYNDRIVERS OFF.

svn path=/trunk/; revision=7091

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