Follow cl-icu 259ee67: no global nickname, BIDI-DIRECTION, load errors
The examples are written in a package that gives cl-icu the local
nickname icu, and cl-harfbuzz hb, which Home, Getting started and
Installation show, since the packages have no global nicknames now.
Loading uses asdf:load-system. The type bidi-direction joins the API
index and the page on bidirectional text. The errors of an ICU that
cannot be loaded or lacks a function are icu-errors, with their new
messages and hints, and a constant argument of the wrong type is a
compiler warning. Development describes the new file layout, the form
of %checked and the new tests.
