title: Explode string only once on first occurring substring
body: <p><code>preg_match()</code> gives one match.<br>
  <code>preg_match_all()</code> returns all matches.<br>
  <code>preg_split()</code> returns all splits.</p>
  <p>How can I split only on the first match?</p>
  <p>Example:</p>
  <pre><code>preg_split(&quot;~\n~&quot;, $string);
  </code></pre>
  <p>This is what I want:</p>
  <pre><code>array(
    0 =&gt; 'first piece',
    1 =&gt; 'the rest of the string
          without any further splits'
  )
  </code></pre>