updated TiddlySpaceInit to refresh SiteIcon's
updated TiddlySpaceInit to refresh SiteIcon's

This code refreshes SiteIcon in the backstage (/bags/.../tiddlers/SiteIcon)
and also any uses of the SiteIcon tiddler (a user may include another space on
creation so feasibly could be using it in other ways)

TiddlySpace/tiddlyspace,FND/tiddlyspace,FND/tiddlyspace,TiddlySpace/tiddlyspace,FND/tiddlyspace,TiddlySpace/tiddlyspace