Add endian.h header for byte order detection. Ensure that headers can be

included individually.

doc/html/index.html

@@ -3,7 +3,7 @@
 <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
 <title>Predef 1.0</title>
 <link rel="stylesheet" href="boostbook.css" type="text/css">
-<meta name="generator" content="DocBook XSL Stylesheets V1.78.0">
+<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
 <link rel="home" href="index.html" title="Predef 1.0">
 <link rel="next" href="predef/introduction.html" title="Introduction">
 </head>
@@ -57,7 +57,7 @@
 </table></div>
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
-<td align="left"><p><small>Last revised: January 19, 2013 at 03:18:05 GMT</small></p></td>
+<td align="left"><p><small>Last revised: March 19, 2013 at 03:53:01 GMT</small></p></td>
 <td align="right"><div class="copyright-footer"></div></td>
 </tr></table>
 <hr>