[PATCH] udevd - allow to bypass sequence number

[PATCH] udevd - allow to bypass sequence number

This patch allows udevsend to be called by the user and not only by the
kernel with its SEQNUM. If no SEQNUM is given, we move the event straight
to the exec queue and don't look if something is missing.

I don't know if this is really needed, but some people seem trying to
send events trough udevd instead of calling udev directly with their
scripts and confuse the reorder logic with that.

So at least, we may remove this source of confusion and udevsend is much
much faster back than udev itself and it will also block concurrent events
for the same devpath.