Refactoring kdesk

 * removed sn_notify from kdesk, it now talks to likdesk hourglass API directly
 * reorganized build order in the makefile (kdesk depends in libkdesk-hourglass now)
 * new method in icon class to retrieve the app’s command line
 * clarified some libkdesk names in the makefile
 * removed duplicated source module for sn_notify callbacks