Option to auto-disable on quit?

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Activate NoSleep (icon turns blue/black)
2. Quit NoSleep
3. Close laptop lid

What is the expected output? What do you see instead?
I would prefer the computer to sleep. Instead, it behaves as though NoSleep has 
disabled its ability to sleep, even though the application is no longer open.

What version of the product are you using? On what operating system?
1.3.3 on OS X 10.8.5.

Please provide any additional information below.
I can see that some people appreciate how the application currently functions. 
Perhaps my preference could be added as an option in the application's 
Preferences? (Presumably, all the app needs to do is check that it is not 
actively preventing sleep before quitting.)

Original issue reported on code.google.com by [email protected] on 5 Nov 2013 at 9:27

[GoogleCodeExporter]

My computer drained its battery overnight, after I accidentally quit NoSleep 
without deactivating — I really would hugely appreciate this feature! Many 
thanks.

Original comment by [email protected] on 2 Apr 2014 at 9:14