Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

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

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

Add META_MODE support.

Off by default, build behaves normally.
WITH_META_MODE we get auto objdir creation, the ability to
start build from anywhere in the tree.

Still need to add real targets under targets/ to build packages.

Differential Revision: D2796
Reviewed by: brooks imp

Sync with NetBSD, mainly address NetBSD bug #43355:

Fix valid_format() to be more careful about allowing only valid
printf formats.

Obtained from: NetBSD
MFC after: 2 weeks

Convert to usr.bin/ to LIBADD
Reduce overlinking

Standardize EXIT STATUS instructions in man pages when possible.

Approved by: bcr (mentor)
MFC after: 3 days

Add missing static keywords to seq(1)

Fix typos.

PR: bin/148894
Submitted by: olgeni

Treat numbers after [Ee] a positive number rather than an invalid
one.

Add seq(1), a small utility to generate sequence number.

Obtained from: NetBSD
MFC after: 3 months