Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Merge r267482,r267483,r267486,r267577,r267671,r267672 from head:

Remove send-pr and fix up all references to it. Replace it with a
stub send-pr directing people towards the web site.

Add a stub send-pr that simply points people towards the online support
pages, to give people used to send-pr a bit of guidance.

MFC after: 3 days