Panel contents translations

[Benedikt Meurer]

Hello translators/developers,

I changed xfce4-panel to use intltool for the contents.xml file as well. 
This breaks all existing translations, as there was no easy way for me 
to extract and merge the existing translations. I left the 
contents.xml.<lang> files in CVS for now, so you can smoothly merge them 
with your .po files. This only affects HEAD for now.

In general, this means that the panel installs only one contents.xml 
file now, not one per language, which makes handling easier for 
translators and developers.

Jasper, I did not change touch your new launcher, but only item.c. But 
as you can see that change to item.c was rather trivial, so you can 
easily port it to your new launcher as well. In addition, you should 
change the function that looks up the contents.xml to not look for 
contents.xml.<lang> files any more, so people upgrading from source will 
get the new contents.

Happy breakage,
Benedikt