tic and a directory terminfo layout

[Roy Marples <roy%marples.name@localhost>]

Hi List!

tic(8) is currently growing some changes.
The big one is the ability to write to a directory/file database rather
than a singular database. The general idea is to use the singular
database for the base system and the directory/file database for pkgsrc.

So ncurses (for the vt220 terminfo file), writes like so:
	/usr/share/terminfo/v/vt220
Aliases are simply symlinks back to the full terminal description file.

For NetBSD terminfo, I'm proposing a similar thing, but with a twist.
A terminal description file ending with .bin (or any other extension if
people are unhappy with .bin) is the pre-compiled one, but without the
extension it remains a text file to be parsed as if it was in $TERMINFO.
This satisfies a complaint about our terminfo made on FreeBSD mailing
lists that it required a binary database rather than just using a plain
text file - .cdb == singular database, .bin == binary blob (what's
actually stored in the database for the term) and no extension is plain
text.

Of course, outside of tic and libterminfo, the actual database itself
remains opaque, so this is just about options of handling the data and
allowing pkgsrc to install it's own terminfo descriptions.
This also fixes PR bin/52208.

Commentary welcome.

Roy