Removing extra whitespace?

There are a few places where Clojure programs can accumulate trailing whitespace. In the listings below `|` denotes the end of the line.

**At the ends of lines after source code**

```clj
(def v nil) |
```

**Between lines of source code within a form**

```clj
(defn best-allowed-language [accepts-header available]
(let [accepts (->> (string/split accepts-header #"[\s\r\n]*,[\s\r\n]*")
(map split-qval)
(into {}))
|
score (fn [langtag]
(or
;; "A language-range matches a language-tag if it exactly equals the tag"
...
```

**At the end of a source code file**

```clj
(def v nil)

|
```

Different programmers and editors have different behaviour for how they treat extra whitespace. This can lead to churn in source control diffs when different programmers work on the same file. I think it would be beneficial for this spec to define a policy for handling extra whitespace. I'm personally in favour of removing all three kinds of whitespace, but would like to open this up for discussion.