Convert bsdinstall/partedit sade(8) for libbsddialog

[asiciliano]

Summary

First try for bsdinstall/partedit sade(8) with libbsddialog.

I am considering a call for testing, hackers@? (Test Plan below).

This review depends on libbsddialog 0.0.2 https://reviews.freebsd.org/D33580

Test Plan

Menu, checkelist, msgbox , yesno and infobox tested via tzsetup, kbdmap and portconfig.

We need to test forms (this is the first real world use/test case).
"Isolation" test with debug symbols:

% git clone https://gitlab.com/alfix/bsddialog.git
% cd bsddialog/
% git clone https://gitlab.com/alfix/freebsd-lab.git
% cd freebsd-lab/bsdinstall/partedit/
% make -DDEBUG
% ./sade

To check:

• Forms: <Create> and <Modify>
• ZFS

[asiciliano]

Update diff:

• fix: style(9) withespace and comment
• delete: useless constant (diskmenu.h)
• fix: focus on the last selected item after a diskmenu refresh (like diskeditor)

[asiciliano]

Abandon Review: a complete libbsddialog version is almost ready, I' ll update a new snapshot and a revision for sade soon.