RFC: Change of context-manager fall-back

[Jens Georg <mail jensge org>]

Hi,

I was wondering if we should change the fall-back chain for our
context-managers. Currently we fall-back to the static dumb Unix manager
if the more sophisticated compiled-in manager is not available.

I'm wondering if we should drop to Linux first (on Linux only obviously)
and only drop to Unix if we don't have netlink available.

Any comments?