Files changed made to add ximage/palette control to xds.

Changes from XDS2.0b -> XDS2.1
==============================
Changes are bracketed by
	#ifdef XIMAGE_PALETTE
	#endif
although its possible I've missed a couple

Makefile	added references to the two new files
gr_def.h	New structure for palette.
gr_anilev.c	Changed calls to gr_LoadPAL to PaletteBox
gr_dicelev.c
gr_dsplev.c
gr_isolev.c
gr_subslev.c
gr_tillev.c
gr_viewlev.c

gr_pal.c	Lots, well, some.

gr_xwi2.c	gr_MakeToggle, gr_MakeTitle
		Added check for width &/or height = 0.

gr_file.c
gr_fillev.c	Added code to support writing of palette files.


Misc

XDS normally uses one colormap per window. The modified version currently
shares one color map among all windows. Other than not being able to have
multiple maps concurrently, the only other disadvantage is that if a
dicer window is chosen, the palette split routines will be called making
non dicer images look strange. This will likely be fixed later.

Changes from XDS2.1 -> XDS2.2
=============================
Instead of using #ifdef XIMAGE_PALETTE (who imply the decision is taken at
compile time and the user can't make the choice) the two versions are
compiled and the one used at run time is choosen from an X resource:
.paletteEditor, whose value is then stored in gr_Data.paletteEditor.
if gr_Data.paletteEditor is true, the palette editor is used, otherwise no.

gr_anilev.c
gr_dicelev.c
gr_dsplev.c
gr_fillev.c
gr_isolev.c
gr_main.c
gr_pal.c
gr_subslev.c
gr_tillev.c
gr_viewlev.c

Creation of an Imakefile.

Support of HDF3.2, including integer data who are then converted to float.
Ability to transpose 3D SDS when they are loaded.
td_hdf.c

Changes from XDS2.2 -> XDS2.3
=============================
When using the palette editor, XDataSlice now use two X Colormap: one
for dicer images and one for the other windows.
gr_pal.c
xi_palette.c

Better DTM support, including use of SRV messages: XDataSlice can
now be used in a Collage session.
Use interleaving scheme when we receive a palette over DTM.
grdtm.c			heavy mods.
gr_main.c
gr_boslev.c
gr_toplev.c

fix some memory leaks
gr_axes.c
gr_box1.c
gr_box2.c
gr_hist.c
gr_xwi2.c

display data using %g format in the spreadsheet
td_axes.c
