Stop Button does not always remove CheckAndInstallAtStartup flag file

[GoogleCodeExporter]

What steps will reproduce the problem?

1. Take a fresh machine
2. Install and configure munki appropriate to your environment
3. Configure your test machine to install a single package
4. Kick-off a bootstrap run by touching the 
.com.googlecode.checkandinstallatstartup flag file on the test machine
5. Wait for MSU to launch and hit the Stop button _after_ the package has been 
downloaded

What is the expected output? 

Munki should stop, remove the flag file, and the bootstrap should be 
discontinued.

What do you see instead?

Munki stops, but does not remove the flag file and so begins another bootstrap 
run. It will continue to do so until the updates are exhausted.

Additional Info:

Whether or not MSU halts seems to be a matter of timing. The behaviour I see 
consistently is that it is impossible to discontinue a bootstrap run by 
clicking Stop during any other phase than the download phase. If the Stop 
button is pressed during Apple Software Updates or installations, MSU _will 
exit_, but the flag file will not be removed and will therefore continue the 
bootstrapping.

This means that if you want to really Stop a bootstrapping run, you need to do 
doe during the early initialization phase, the checking for updates phase, or 
the downloading phase. Clicking stop during any other operation does not appear 
to remove the flag file.

Original issue reported on code.google.com by daygloje...@gmail.com on 11 Feb 2014 at 7:25

[GoogleCodeExporter]

I would like to amend this statement:

"The behaviour I see consistently is that it is impossible to discontinue a 
bootstrap run by clicking Stop during any other phase after the download phase."

Original comment by daygloje...@gmail.com on 11 Feb 2014 at 7:31