Remove $FreeBSD$: two-line nroff pattern

Remove /^\.\\"\n\.\\"\s*\$FreeBSD\$$\n/

For man page references found in ports, indicate the respective port.

Language fixes.

Submitted by: wblock
MFC after: 2 weeks

Revert to pre-r318116 wording to not give the false impression
that setting the kernels' idea of terminal size is somehow an
alternative to environment variables.

Reported by: kib
MFC after: 2 weeks
Sponsored by: DARPA, AFRL

Random updates to resizewin(1) man page.

Reviewed by: cem, Daniel O'Connor <darius@dons.net.au>
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D10640

Add resizewin -z. It makes resizewin not do anything if the terminal
size is already set to something other than zero. It's supposed to be
called from eg /etc/profile - it's not neccessary to query terminal
size when logging in over the network, because the protocol used already
takes care of this, but it's neccessary when logging over a serial line.

Reviewed by: cem, Daniel O'Connor <darius@dons.net.au>
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D10637

Make resizewin.1 manpage use .Fx macro

Fix capitalization of "PuTTY" also.

MFC after: 1 week

Fix a mandoc -Tlint warning

Add a small tool, resizewin(1), to query terminal for window size

Submitted by: Daniel O'Connor
Reviewed by: kan, wblock, cem
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D4438