Reverted one of the previous changes to make the Octave binding build in a separate build tree.  With the wrong --cpp_ignore option, compilation fails in the CVS checked out tree.
Reverted one of the previous changes to make the Octave binding build in a
separate build tree.  With the wrong --cpp_ignore option, compilation fails
in the CVS checked out tree.

svn path=/trunk/; revision=5805

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