udev: warn when name_to_handle_at is not implemented

We have a bunch of reports from people who have a custom kernel and
are confused why udev is not running. Issue a warning on
error. Barring an error in the code, the only error that is possible
is ENOSYS.

https://bugzilla.redhat.com/show_bug.cgi?id=1072966
bootchart: add control group option
bootchart: rewrite usage message more generally
bootchart: print to stdout and display default values in help