juju should read a system file like distro-info for Mac versions

[John A Meinel]

when the patch to support Mac versions lands: https://code.launchpad.net/~jameinel/juju-core/darwin-os-version/+merge/218357 it will have hard-coded what OS X Kernel version maps to what Mac code name. (so kernel 13 is Mavericks, and 12 is Snow Leopard, etc).

However, it would be nice if we had something like distro-info's ubuntu.csv that would allow us to read a file to know about newer versions without having to recompile Juju to add that information.

This isn't particularly important until we start supporting OS X as a workload rather than just a client.

It might be nice if we could just configure simplestreams descriptions, since we'd need that information in order to find target images anyway. We could potentially have a small mapping from Kernel Major version into code name (series) and then index the rest on series.

[Curtis Hovey (sinzui)]

This issue is a subset of bug 1465317