setting a max-step for event-dispatch so that select, epoll_wait, etc. are called with a timeout
multiplexer now defaults to select...

adding:
multiplexer keyword argument to with-open-bus
#'available-multiplexers utility
Merge branch 'master' of https://github.com/joseph-gay/dbus
Renamed the function get-machine-id
Export 'update-environment-variables'