Join String list elements with a delimiter in one step
<p>Is there a function like join that returns List's data as a string of
all the elements, joined by delimiter provided?</p>

<pre><code> List&lt;String&gt; join; ....
 String join = list.join('+");
 // join == "Elem 1+Elem 2";
</code></pre>

<p>or one must use an iterator to manually glue the elements?</p>
