* The array "subject" of a function gets called $array.
* Further parameters should be self-descriptive if used
as a named parameter, and a full word, not an abbreviation.
* If there is a "bunch more arrays" variadic, it gets
called $arrays (because that's what was already there).
* A few functions have a variadic "a bunch more arrays,
and then a callable", and were already called $rest.
I left those as is and died a little inside.
* Any callable provided to an array function that acts
on the array is called $callback. (Nearly all were already,
I just fixed the one or two outliers.)
* array_multisort() is beyond help so I ran screaming.
