[sugar] [PATCH hardware-manager] Allow entering kernel suspend. Hi,

Here's a patch to allow going to full kernel suspend ("S3") via the
hardware-manager.  It applies on top of the previous DCON patch.

Note that this allows a non-root process to take us into suspend; I
don't see a way around this while we're having individual activities
tell us when suspend is appropriate, rather than working it out for
ourselves.  Again, the first caller of this will be Read.activity,
but anything that only updates itself in response to user input
would be appropriate later.

Thanks!

- Chris.

