Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Correct spelling.

Submitted by: (pluknet gmail.com)
MFC after: 4 days
X-MFC with: r201806

Switch traceroute over to make use of proper in-kernel source
address selection.

Reviewed by: rwatson, fenner
MFC after: 1 week
X-MFCable to: stable/8, stable/7 (after r183571).
PR: kern/139454
Tested by: Frank Steinborn (steinex nognu.de)