Create a kbackgroundsnapshot.
It's just a command line which allows to make screenshot directly and store picture on desktop 'a la MacOsX'
It's easier than :
-> launch ksnapshot
-> select type of snapshot
-> create snapshot
-> select filename for snapshot
-> save snapshot

kbackgroundsnapshot is just one snapshot, but if we add global shortcut for each type of snapshot we can make life more easy I think.

Fix mem leak into ksnapshot.