dbus: FreeBSD kqueue expertise needed

[Colin Walters]

Heads up, as part of this bug:

http://bugs.freedesktop.org/show_bug.cgi?id=21597

We need to change the (internal) abstraction API for monitoring
directories.  This patch has the relevant changes done for
Linux+inotify, because I can test that myself.  The others (kqueue
namely), I'd really appreciate if someone who knows kqueue could step
in and add a patch before the 1.2.18 release which I'd like to be
soon.