Double precision image support.
-------------------------------

I modified the following files to add a double precision image type
(bitpix -64):
---
astrotcl/imageio/include/ImageIO.h
astrotcl/imageio/src/FitsIO.C
rtd/rtdimg/src/RtdCamera.C
rtd/rtdimg/src/RtdImage.C
rtd/rtilib/include/NativeImageData.h
rtd/rtilib/src/ImageData.C
rtd/rtilib/src/ImageTemplates.C
rtd/rtilib/src/Makefile.in
rtd/rtilib/src/NativeImageData.C
---
and created the following files:
---
rtd/rtilib/include/DoubleImageData.h
rtd/rtilib/src/DoubleImageData.C

Peter W. Draper (p.w.draper@durham.ac.uk)

31st May 2001.
