Add a WITHOUT_DIALOG src.conf(5) knob.

It also turns off dependencies (bsdinstall, bsdconfig, dpv, tzsetup).

the 10.4 release cycle, also belatedly marking the official start
of the code slush.

Set the default mdoc(7) version to 10.4, and update the clang(1)
TARGET_TRIPLE to reflect 10.4. While at it, add missing FreeBSD
major versions to mdoc(7).

Approved by:	re (implicit)

Even though gdb and kgdb may not be removed for 12.0 on some architectures,
the notice is unconditional as these tools will likely be removed at some
point in the future when adequate replacements are available (gdb in ports
or lldb in base).

Use SRCTOP-relative paths to other directories instead of .CURDIR-relative ones

This simplifies pathing in make/displayed output

r289172:

Refactor the test/ Makefiles after recent changes to bsd.test.mk (r289158) and
netbsd-tests.test.mk (r289151)

- Eliminate explicit OBJTOP/SRCTOP setting
- Convert all ad hoc NetBSD test integration over to netbsd-tests.test.mk
- Remove unnecessary TESTSDIR setting
- Use SRCTOP where possible for clarity

r290254:

Remove unused variable (SRCDIR)

r306740:

groff: use changelog date rather than file modification date in man pages

The source checkout date is not particularly relevant, and this makes
groff man pages build reproducibly.

r307150:

Avoid using 'head' in generating groff doc date

It may not be available in certain cross build cases.

Note that this is a slight change in functionality, in that now only the
first line of the source ChangeLog file is processed. This is acceptable
as groff will be retired and we won't encounter a possibly-different
ChangeLog format.

Sponsored by:	The FreeBSD Foundation

marking the official start of the code slush.

Set the default mdoc(7) version to 10.3, and update the
clang(1) TARGET_TRIPLE and BUILD_TRIPLE to reflect 10.3.

Approved by:	re (implicit)

Record dependencies of gdb/gdbtui/kgdb on binutils/lib{bfd,iberty,opcodes},
fixing parallel builds.

  Fix ld not respecting --sysroot.

Relnotes:	yes