[kadingira] Selecting languages

[Javier Bezos]

Hi all,

I think it's time to revamp the babel interface to select
languages. Currently there are 4 ways:

-- \selectlanguage   (1)
-- otherlanguage     (1)
-- otherlanguage*    (2)
-- \foreignlanguage  (2)

There is also an experimental \foreignlanguage* for a few
lines of “reversed” text (R inside L or L inside R.)

There are two groups performing different tasks:
1) set \language (ie, hyphenation patters): -- 12
2) set hyphenmins -- 12
3) write the language to the aux files -- 1
4) switch captions and date -- 1
5) perform “extras” (ie, \extras... and \noextras) -- 12
6) set the font, if \babelfont is used -- 12
7) set the text direction -- 12
8) set the par direction (and boxes in lua) -- 1
9) ensure hmode (\foreignlanguage)

One of the things I'd like to do is decoupling the language
in the babel sense from the language in the TeX sense. To
make clear this distinction, babel will introduce the
concept of locale, which is universally used elsewhere.

Just some preliminary thoughts.

Javier