Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

Upgrade jail(2) to latest jail(2) API to make the regression test work
again. Eventually should switch to jail_set(2).

Reported by: rwatson
MFC after: 10 days

Style: NO_MAN doesn't need any value.

Change jail IP from 1.0.0.127 to 127.0.0.1, which shows, that this test
doesn't examine the real issue as it pass without problems.

Use WARNS?= instead of WARNS= in Makefiles so that global warning
settings can override local ones.

Pointed out by: ru

In refactoring the test before committing, a pointer was passed instead
of a structure for the sockaddr_in. Pass the pointer to connect()
instead of the pointer to the pointer.

Specify a port number to connect to.

Add udpconnectjail, a simple regression test to exercise an (as yet)
unfixed bug in the jail() implementation relating to using the connect()
system call on UDP sockets.

PR: 26506