title: Can't install phpDocumentor via Composer
body: <p>In composer.json I've got</p>
  
  <pre><code>{
      "require":
      {
          "phpdocumentor/phpdocumentor": "*"
      }
  }
  </code></pre>
  
  <p>It's what is there because I'm trying to install phpDocumentor into an isolated folder with <code>./composer.phar install</code> command. But what I'm getting is</p>
  
  <pre><code>Loading composer repositories with package information
  Updating dependencies (including require-dev)
  Your requirements could not be resolved to an installable set of packages.
  
    Problem 1
      - phpdocumentor/phpdocumentor v2.0.0 requires phpdocumentor/template-abstract ~1.2 -&gt; satisfiable by phpdocumentor/template-abstract[1.2, 1.2.1].
      - phpdocumentor/phpdocumentor v2.0.1 requires phpdocumentor/template-abstract ~1.2 -&gt; satisfiable by phpdocumentor/template-abstract[1.2, 1.2.1].
      - phpdocumentor/phpdocumentor v2.1.0 requires phpdocumentor/template-abstract ~1.2 -&gt; satisfiable by phpdocumentor/template-abstract[1.2, 1.2.1].
      - phpdocumentor/phpdocumentor v2.2.0 requires phpdocumentor/template-abstract ~1.2 -&gt; satisfiable by phpdocumentor/template-abstract[1.2, 1.2.1].
      - phpdocumentor/phpdocumentor v2.3.2 requires phpdocumentor/template-abstract ~1.2 -&gt; satisfiable by phpdocumentor/template-abstract[1.2, 1.2.1].
      - phpdocumentor/phpdocumentor v2.4.0 requires phpdocumentor/template-abstract ~1.2 -&gt; satisfiable by phpdocumentor/template-abstract[1.2, 1.2.1].
      - phpdocumentor/phpdocumentor v2.3.1 requires dompdf/dompdf dev-master@dev -&gt; no matching package found.
      - phpdocumentor/phpdocumentor v2.3.0 requires dompdf/dompdf dev-master@dev -&gt; no matching package found.
      - phpdocumentor/template-abstract 1.2.1 requires ext-xsl * -&gt; the requested PHP extension xsl is missing from your system.
      - phpdocumentor/template-abstract 1.2 requires ext-xsl * -&gt; the requested PHP extension xsl is missing from your system.
      - Installation request for phpdocumentor/phpdocumentor * -&gt; satisfiable by phpdocumentor/phpdocumentor[v2.0.0, v2.0.1, v2.1.0, v2.2.0, v2.3.0, v2.3.1, v2.3.2, v2.4.0].
  
  Potential causes:
   - A typo in the package name
   - The package is not available in a stable-enough version according to your minimum-stability setting
     see &lt;https://groups.google.com/d/topic/composer-dev/_g3ASeIFlrc/discussion&gt; for more details.
  </code></pre>