With GNU diff and cdialog gone, this is now an empty shell.

Reviewed by:	markj
Differential Revision:	https://reviews.freebsd.org/D55425

This is the last remaining piece of GPL software in the base system.
The installer transitioned to bsddialog four years ago, and the last
remaining dialog consumer, dpv, was turned off more than two years ago.
Retire dpv, libdpv, libfigpar (used only by dpv), and dialog itself.

Reviewed by:	dteske
Differential Revision:	https://reviews.freebsd.org/D55424

This reverts commit 5b2bdadeb6c25c10dac9722fd66a668e14d3b384.

This reverts commit 9cc87ca23d9ccae814bea514aa4bdc791f2d6e46.

With GNU diff and cdialog gone, this is now an empty shell.

(cherry picked from commit 151dd62e005119dda24b8ff9b14aa5beaaa681ac)

This is the last remaining piece of GPL software in the base system.
The installer transitioned to bsddialog four years ago, and the last
remaining dialog consumer, dpv, was turned off more than two years ago.
Retire dpv, libdpv, libfigpar (used only by dpv), and dialog itself.

(cherry picked from commit 73bb4a92985d747462d866248c1e7623f7ff1a7f)

This is a residual of the $FreeBSD$ removal.

MFC After: 3 days (though I'll just run the command on the branches)
Sponsored by: Netflix

Remove /^\s*#[#!]?\s*\$FreeBSD\$.*$\n/

Unconditionally install bsdgrep as grep, bootstrap or not. Remove all
build glue and stop installing both gnugrep and libgnuregex now that
all consumers of the latter are gone.

Relnotes:	yes
Differential Revision:	https://reviews.freebsd.org/D27732