Async DBusMessage reads using the C API

[Havoc Pennington]

Hi,

My suggestion is dbus_connection_read_write() which would be more
flexible; you could then mix that with dbus_connection_pop_message() to
do what you want, or dbus_connection_dispatch(). read_write() should
probably block by default, though I guess having an argument for whether
to block is possible.

I wonder if we should have dbus_connection_pop_message() given the huge
caveats in its API docs. It's sort of a dbus_shoot_me_in_foot()
function. I guess we use it in a lot of the test code though ;-)

Havoc