Changed icon create/edit dialog, so working path can be set, including startup options like running in terminal or starting with startup nofication hints.
Changed how icons are started. Previously, ede-desktop would extract content from .desktop Exec key and explicitly run it. This would not correctly handle other .desktop details, like startup notification or running in terminal. Now, full .desktop path is sent directly to ede-launch which will take care about named startup details.
These changes also fixes bug #235: "Working directory and startup notification for desktop icons".