windows shutdown handling

[Akuli]

<Arrinao> ! no dialog ('unsaved changes do you really wanna quit?')  upon closing
<Arrinao> actually
<Arrinao> I think I just shut down windows
<Akuli> how would you expect porcupine to know when your operating system shuts down? :D
<Arrinao> but there should be something for windows to display the 'this app is preventing windows from shutting down'
<Arrinao> well other programs do know
<Arrinao> or they don't, but they have some kind of priority
<Arrinao> for example ms word will display this

[Akuli]

Must make sure that opened tabs are remembered too