bsddialog: import version 0.2

[asiciliano]

Summary

This version provides improvements and fixes mainly to use bsddialog-utility in bsdinstall/scripts.
The lib API is not broken so the previous converted utilities tzsetup, distextract, etc. are OK,
a wiki page tracks the current status: https://wiki.freebsd.org/RoadmapFromDialogToBSDDialog.

This review changes contrib/bsddialog to allow to test the review locally,
of course I' ll follow "Committer' s Guide 5.4. Vendor Imports with Git" to create a worktree, tag, etc, before to commit the review.

CHANGELOG:

Utility:

• add: CHANGELOG file.
• add: "menus" print item with focus (except with OK and ERROR).
• add: pause.sh example.
• add: timebox.sh example.
• change: --theme name "default" -> "flat".
• delete: treeview.sh example.
• fix: --separate-output does not quote (except with --quoted).
• fix: --datebox and --date-format month in output.
• improve: examples handle exit status.

Library:

• add: conf.form.enable_wchar for wide characters in bsddialog_form().
• add: theme.menu.f_selectorcolor.
• add: formw.c example.
• change: move conf.f1_file and conf.f1_message in conf.key.
• change: theme.button.[left|right]ch -> theme.button.[left|right]delim.
• change: theme.button.space -> theme.button.hmargin.
• change: theme.menu.arrowcolor -> theme.dialog.arrowcolor.
• change: default menu item depth 4 -> 2.
• fix: disable HOME, PPAGE, END and NPAGE keys in bsddialog_form().
• fix: visible cursor for timebox.c and form.c in VM VirtualBox.
• fix: mixedlist, center position of separator with big pad.
• fix: timebox and datebox set values only with BSDDIALOG_OK.
• fix: menurows autosize with fullscreen.
• fix: bar color with 0%.
• fix: bar label position.
• improve: timebox and datebox navigation (keys, buttons and shortcuts).
• improve: "menus" colors for accessibility.

Test Plan

Examples in examples_utility/ and examples_library/ test the changes.