[BRLTTY] BrlAPI and dot string <-> dot integer conversion

[Samuel Thibault]

Hi,

Ok, just to sum it up:

- we agree that this is not really related to BrlAPI itself
- gnome-braille or any such dot translation library is probably not the
right place either
- these are trivial functions that may be implemented via macros and
inline functions, thus no need for a real _library_, but just a header.

Now, it happens that the dot encoding system that brlapi uses is called
ISO 11548-1.  Maybe we could just write an iso_11548_1.h header
containing the macros and inline functions we talked about (as well as
an equivalent of the BRL_DOT[1-8] macros)?

Samuel