All PDF functions changed to accept a pointer to a PDFstrm instead of a file handle, to enable PDF operations to/from a memory buffer. New PDF front-ends to fopen, fclose, getc, putc added.  pdf_bopen() added for initialization of memory buffer.
All PDF functions changed to accept a pointer to a PDFstrm instead
of a file handle, to enable PDF operations to/from a memory buffer.
New PDF front-ends to fopen, fclose, getc, putc added.  pdf_bopen()
added for initialization of memory buffer.

svn path=/trunk/; revision=644

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