converted page footer navigation bars to three-cell tables in all *.dox

also relaxed table widths in intro.dox to use 100% instead of 700 pixels
to fit with doxygen header rule and new footer navigation bars



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6724 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

documentation/src/editor.dox

@@ -891,10 +891,28 @@ style_parse(const char *text,
 }
 \endcode
 
+
 \htmlonly
 <hr>
-<a class="el" href="index.html">[Index]</a> &nbsp;&nbsp;
-<a class="el" href="common.html">[Previous]&nbsp; Common Widgets and Attributes</a>&nbsp;
-<a class="el" href="drawing.html">[Next]&nbsp; Drawing Things in FLTK</a>&nbsp;
+<table summary="navigation bar" width="100%" border="0">
+<tr>
+  <td width="45%" align="LEFT">
+    <a class="el" href="common.html">
+    [Prev]
+    Common Widgets and Attributes
+    </a>
+  </td>
+  <td width="10%" align="CENTER">
+    <a class="el" href="main.html">[Index]</a>
+  </td>
+  <td width="45%" align="RIGHT">
+    <a class="el" href="drawing.html">
+    Drawing Things in FLTK
+    [Next]
+    </a>
+  </td>
+</tr>
+</table>
 \endhtmlonly
+
 */