NUL must be a first class citizen [was: Some groundwork for Unicode in Zle]

["Matthias B." <msbREMOVE-THIS@xxxxxxxxxxxxxxx>]

This is not directed at anyone in particular. I just want to remind
everyone working on this that ASCII NUL (i.e. the character with ASCII
code 0) is a valid (and very useful) character and must be a first-class
citizen that has to work everywhere you could use the letter "A"  (except
of course where restrictions beyond the scope of zsh forbid it, e.g. when
passing file names to system calls).

If 0-terminated wchar_t strings are to be used, then NUL has to be
remapped or escaped, so that it's not encoded as 0, just as it is done in
zsh currently.

The following has to keep working:

x=$(find . -print0)
# Process x in many useful ways

MSB

-- 
Modesty marks the wise.