[wwwdocs] Fix main page

[Gerald Pfeifer]

Something must have gone awry with our main page during the last
stages of the HTML 5 conversion.  I noticed this yesterday and
fixed it on the spot with the patch below.

More CSS, though not exactly beautiful.  As a next step, I'll see to 
reduce the use of tables for our main page; it should not be necessary 
any longer with modern HTML and CSS.  Anyone who wants to lend a helping 
hand is definitely welcome!

Gerald

Index: gcc.css
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/gcc.css,v
retrieving revision 1.62
retrieving revision 1.64
diff -u -r1.62 -r1.64
--- gcc.css	3 Sep 2018 18:55:18 -0000	1.62
+++ gcc.css	3 Sep 2018 19:43:07 -0000	1.64
@@ -21,6 +21,7 @@
 .top      { vertical-align:top; }
 
 .width33  { width:33%; }
+.border0  { border-width:0; }
 
 .no-margin-top { margin-top:0; }
 .twocolumns { column-count:2; }
@@ -43,10 +44,13 @@
 
 table.nav {
   padding-left: 32px;
-  border-width: 0;
   border-spacing: 0pt;
 }
 
+table.nav td {
+  border-width: 0;
+}
+
 table.navitem {
   width: 100%;
   border-spacing: 0pt;
Index: style.mhtml
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/style.mhtml,v
retrieving revision 1.148
retrieving revision 1.151
diff -u -r1.148 -r1.151
--- style.mhtml	1 Sep 2018 23:39:53 -0000	1.148
+++ style.mhtml	3 Sep 2018 19:34:55 -0000	1.151
@@ -70,10 +70,10 @@
 
 <if <var-exists navigation>
  <group
-  <table style="border-width:0;" cellspacing="0">
+  <table class="border0" cellspacing="0">
   <tr>
 
-  <td valign="top" width="99%">                           <!-- main frame -->
+  <td class="top border0" width="99%">                    <!-- main frame -->
  >
 >
 
@@ -83,7 +83,7 @@
  <group
   </td>                                            <!-- end of main frame -->
 
-  <td valign="top">                                        <!-- nav frame -->
+  <td class="top border0">                                 <!-- nav frame -->
   <table class="nav" width="10em">
 
   <tr><td><table class="navitem">
Index: index.html
===================================================================
RCS file: /cvs/gcc/wwwdocs/htdocs/index.html,v
retrieving revision 1.1096
retrieving revision 1.1099
diff -u -r1.1096 -r1.1099
--- index.html	1 Sep 2018 23:42:00 -0000	1.1096
+++ index.html	3 Sep 2018 19:28:26 -0000	1.1099
@@ -46,14 +46,14 @@
 <!-- ==================================================================== -->
 
 
-<table><tr>
+<table class="border0"><tr>
 
 <!-- Note: We usually want to rotate news to the "old news" page when
      it's more than 12 months old or the News pane on this page has
      become longer than the parallel one, whatever happens first. 
 -->
 
-<td class="news">
+<td class="news border0">
 <h2 id="news">News</h2>
 <dl>
 
@@ -110,7 +110,7 @@
 
 
 
-</td><td class="status">
+</td><td class="status border0">
 <h2>Supported Releases</h2>
 <dl>