libopvprpdlpso.* - RPDL driver based on OPVP interface

This project will implement OPVP[1] interface with porting
from Ricoh Ghostscript fork[2].

NOTE: this project is just started, have no function yet.

To test this driver,
0) Install the driver.
   To know how to build this driver, see the INSTALL file.

1) Check if Ghostscript has the "opvp" driver.
   "http://opfc.sourceforge.jp/install.html.en" will help you
   to understand how to check and install it.

2) Prepare an example data to test the driver. If you have a
   PostScript data "example.ps", start the driver test as
   following.
 $ test/gstest.sh example.ps
   This script forks Ghostscript, and Ghostscript loads the
   "libopvprpdl" driver, and render the data you gave.

   Instead of PostScript file, you can use any example file
   that Ghostscript handles, such as PDF.

[1] ftp://ftp.pwg.org/pub/pwg/fsg/vector/pdapi-spec-1.0rc5.pdf
    (currently work in progress)
[2] http://www.ricoh.co.jp/dspinfo/orca/obj/cnt_gs_v871.html