XfceIconTheme fixes

[Jasper Huijsmans]

Brian J. Tarricone wrote:
> jasper,
> 
> this patch looks good, except that there's no need to keep the theme 
> name around or to compare it to a portion of the pathname (which could 
> be error-prone, btw).  the XfceIcon struct has a "is_in_theme" boolean 
> var that you can check.  could you rewrite your patch to use that 
> instead?  if i'm totally missing the point of what you did, feel free to 
> smack me ^_~.
> 

Hmm, yeah, I took the easy way out, I confess ;) The reason of course 
being that XfceIcon is not exposed to the list lookup function. Nor is 
an XfceIcon always used in the icon lookup: the fallback search just 
returns a filename.

I'll just make a private lookup function that also returns the in_theme 
boolean. To make it even more 'complicated' I could make the 
disctinction between inherited and fallback icons, but that does take a 
little more time.

Let me know if you have different (better? ;) ideas.

	Jasper