Super Putty does not save session changes on exit

[GoogleCodeExporter]

In the session treeview there is a simple guard to prevent excessive file saves 
by delaying before saving.

If a node is moved then superputty is closed shortly after the session the move 
will not be saved.

I suggest simply adding SuperPuTTY.SaveSessions(); to exit for a quick fix.

Another possible quirk is that from reading the code it looks like if you keep 
moving nodes quickly it wont save until sometime after you stop. However I have 
not tested this.

However I suggest refactoring the system. It would be a lot easier to manage if 
the session were in its own class and the anti-save spam handling implemented 
there. This would make it much easier to manage auto-saving and auto-backup on 
tree changes gracefully. It would also make it easier to add a property such as 
IsSaved that could be checked on program shutdown.

Original issue reported on code.google.com by j...@gimo.co.uk on 22 Apr 2015 at 11:05