Removing the watch_all

[Drew Moseley]

> libhal.c and libhal.h define a function libhal_device_property_watch_all()
> allowing a callback on any device changed.  There is not a corresponding
> remove function that I could find.  I was triggering a resource fault
> (too many watches not surprisingly) in network manager by continually
> restarting hal.  I added the function shown below and ensured that the
> hal_deinit() function in network manager called this and that seemed to
> resolve the issue.

No feedback on this yet.  Is this something that should go into the main
HAL sources or is there a better way to handle this?

Thanks,
Drew