Add support for minimum_munki_version in PkginfoForAppleSoftwareUpdates

[GoogleCodeExporter]

Due to an issue that surfaced when Apple release 10.8.4, Munki (builds previous 
to 0.9.0.1792.0), would hang at the loginwindow while running postflight 
scripts. This was fixed in build 0.9.0.1792.0, however, there is currently not 
a way to require the fixed build to be installed before the 10.8.4 update is 
offered for install.

A solution to this would be to add support for the existing key 
"minimum_munki_version" to PkginfoForAppleSoftwareUpdates, whereby, if the 
minimum munki version is not met, MSU will not make 10.8.4 available for 
install.

More discussion here: 
https://groups.google.com/forum/?fromgroups#!topic/munki-dev/G5naHRL6IYQ
and here: 
https://groups.google.com/forum/?fromgroups#!topic/munki-dev/gUrtjl21Ut8

Original issue reported on code.google.com by hfi...@gmail.com on 13 Jun 2013 at 8:59

[GoogleCodeExporter]

While this would be useful in circumstances like those noted, the change does 
sound like it would complicate Munki runs.

I've more or less come to the relunctant conclusion that the best way to deal 
with the current v10.8.4 upgrade situation is to manually import the combo 
update into the Munki repo. Set the desired pkginfo flags (like 
minimum_munki_version) on that package.

You may have other updates, like refreshed postflight scripts, that need to be 
installed first. In that case, you could set them as "required" by the update 
to Munki core (if you haven't yet deployed the latest Munki core) and/or the OS 
X Update (if you have deployed Munki core). Make sure all the prerequisites to 
the OS X Update run as unattended_installs, if at all possible.

This gives all the control needed, plus a good deal more scoping capability and 
more.

You can make the OS X Update available via SUS later at your discretion, with 
the understanding that it may result in support calls.

Original comment by jaha...@gmail.com on 15 Jul 2013 at 5:07