[wwwdocs] Completely switch navigation bar to CSS

[Gerald Pfeifer]

Introduce a new CSS class "middle".  Use that for the icons in the
navigation bar instead of align="middle" (except one case where it
is not necessary at all).

Applied, and I also regenerated the pages on gcc.gnu.org.

As a side note, this actually looks better now!

Gerald

Index: gcc.css
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc.css,v
retrieving revision 1.66
diff -u -r1.66 gcc.css
--- gcc.css     9 Sep 2018 20:14:10 -0000       1.66
+++ gcc.css     9 Sep 2018 21:16:35 -0000
@@ -19,6 +19,7 @@
 .right    { text-align:right; }
 .center   { text-align:center; margin-left:auto; margin-right:auto; }
 .top      { vertical-align:top; }
+.middle   { vertical-align:middle; }
 
 .width33  { width:33%; }
 .border0  { border-width:0; }
Index: style.mhtml
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/style.mhtml,v
retrieving revision 1.154
diff -u -r1.154 style.mhtml
--- style.mhtml 9 Sep 2018 09:39:18 -0000       1.154
+++ style.mhtml 9 Sep 2018 21:16:35 -0000
@@ -97,19 +97,19 @@
   <div class="center">
   <a href="https://twitter.com/gnutools";>
     <img src="<get-var BACKPATH>twitter-bird-light-bgs.png"
-      height="42" width="42" align="middle" alt="@gnutools on Twitter"
+      height="42" width="42" class="middle" alt="@gnutools on Twitter"
       />@gnutools</a>
   </div>
   <div class="center">
   <a href="https://plus.google.com/108467477471815191158";>
     <img src="<get-var BACKPATH>gplus-32.png"
-      height="24" width="24" align="middle" alt="gnutools on Google+"
+      height="24" width="24" class="middle" alt="gnutools on Google+"
       />  gnutools</a>
   </div>
   <div class="center">
   <a href="https://my.fsf.org/civicrm/contribute/transact?reset=1&amp;id=57";>
     <img src="<get-var BACKPATH>donate-110-23.png"
-      height="23" width="100" align="middle" alt="Donate to GNU Toolchain Fund"
+      height="23" width="100" alt="Donate to GNU Toolchain Fund"
       /></a>
   </div>
   </td></tr>