ch04 contains the following example programs:

xbitmap1:	simplest bitmap editor, using BitmapEdit widget

xbitmap2:	add small pixmaps to xbitmap1, using XmDrawingArea

xbitmap3:	add small pixmaps to xbitmap1, using XmPrimitive

xbitmap4:	implement xbitmap1, not using BitmapEdit widget

xbitmap5:	both reads and writes standard bitmap files, using BitmapEdit

BitmapEdit.c:	source file for BitmapEdit widget, described in chapters 
		6 and 7

BitmapEdiP.h:	private include file for BitmapEdit, described in Chapter 6

BitmapEdit.h:	public include file for BitmapEdit, described in Chapter 6
