Graphical Object Tagging (GOT)

The bitrgbtags is a non-standard printer device that supports tagging
graphical objects according to type, where types are: text, image,
vector and unspecified.  The type is encoded as a byte and interleaved
in the framebuffer.  Each pixel has a tag.

limitations and oddities:
  o GOT doesn't band.  In fact the the device prototype disables banding.
  o GOT always has 24 bits of color with 3 components.
  o GOT uses a global variable to maintain its state.
  o GOT currently breaks raster operations.
  o GOT hasn't been tested much.

tools (dotags.sh and friends)

  dotags.sh <pcl_file> produces 

     o bit.tmp - bitrgb file with pixel tags for object types.
     o bit_detagged.tmp.ppm - the file stripped of tags and converted to
       ppmraw output.
     o bit.tmp.ppm - detagged bit file converted to ppmraw output.
     o tag.tmp.ppm - a color coded by object type version of the output
          unknown - white
          untouched - yellow
          text - red
          image - green
          path - blue

   dotags.sh will display the output file and tag using imagemagick.

   dotags.sh uses the helper C programs tagimage.c and detag.c

   dotags.sh should only be run in tools/tags after the bittagrgb device
   has been compiled into ../../main/obj/pcl6 executable.
