GTK Icon Cache and dh_iconcache usage

[Jani Monoses]

Hi

> All the other applications need to add it to debian/rules, everything
> else will be taken care of. The list of packages is available at [1] and
> if you plan an upload of a package in question, please tick it off.
> 
> [1] https://wiki.ubuntu.com/DhIconCacheChanges

the xfce CDBS class needs to be made to call dh_iconcache too and that 
solves the xfce apps in that list.

Jani