It's now good enough to do so.
We don't allow grid-alignment:
```fish
complete -c foo -s b -l barnanana -a '(something)'
complete -c foo -s z -a '(something)'
```
becomes
```fish
complete -c foo -s b -l barnanana -a '(something)'
complete -c foo -s z -a '(something)'
```
It's just more trouble than it is worth.
The one part I'd change:
We align and/or'd parts of an if-condition with the in-block code:
```fish
if true
and false
dosomething
end
```
becomes
```fish
if true
and false
dosomething
end
```
but it's not used terribly much and if we ever fix it we can just
reindent.
Do this only when splitting on IFS characters which usually contains
whitespace characters --- read --delimiter is unchanged; it still
consumes no more than one delimiter per variable. This seems better,
because it allows arbitrary delimiters in the last field.
Fixes#6406
This splits a string into variables according to the shell's
tokenization rules, considering quoting, escaping etc.
This runs an automatic `unescape` on the string so it's presented like
it would be passed to the command. E.g.
printf '%s\n' a\ b
returns the tokens
printf
%s\n
a b
It might be useful to add another mode "--tokenize-raw" that doesn't
do that, but this seems to be the more useful of the two.
Fixes#3823.
