Update to Italian translation

Hi,
I am a translator to Italian in the KDE project. I had to figure out a way to 
put in the correct quotes for Italian («» instead of “”), and I ended up 
making quite a few fixes to the it.xml file. The resulting gzipped file is 
attached.

I took the file from trunk/gentext/locale, I hope it is the right place:
http://docbook.svn.sourceforge.net/viewvc/docbook/trunk/gentext/locale/it.xml?view=log

I'm not sure of your policy regarding this matter, but if it is all right, can 
you commit this to your Subversion repository?

Cheers,
-Federico