Store only one copy of the pixel data for symlinked icons. To achieve

Store only one copy of the pixel data for symlinked icons. To achieve

2005-08-14  Matthias Clasen  <mclasen@redhat.com>

	* gtk/updateiconcache.c: Store only one copy of the pixel data
	for symlinked icons. To achieve this, maintain a hashtable
	mapping pathnames to pixel data, and share the pixel data for
	all symlinks resolving to the same pathname. When writing out
	the image data, write out the pixel data only the first time
	it is met, and store the offset pointing to the first copy
	for use in all later cases.
	This reduces the size of the Bluecurve icon cache from 40
	to 13MB. (#312972)