docs: update calendar, add news and link release notes for 18.1.9

docs/index.html

@@ -15,6 +15,16 @@
 <div class="content">
 
 <h1>News</h1>
+<h2>September 24, 2018</h2>
+<p>
+<a href="relnotes/18.1.9.html">Mesa 18.1.9</a> is released.
+This is a bug-fix release.
+<br>
+NOTE: It is anticipated that 18.1.9 will be the final release in the
+18.1 series. Users of 18.1 are encouraged to migrate to the 18.2
+series in order to obtain future fixes.
+</p>
+
 <h2>September 21, 2018</h2>
 <p>
 <a href="relnotes/18.2.1.html">Mesa 18.2.1</a> is released.

docs/release-calendar.html

@@ -39,13 +39,6 @@ if you'd like to nominate a patch in the next stable release.
 <th>Notes</th>
 </tr>
 <tr>
-<td rowspan="1">18.1</td>
-<td>2018-09-21</td>
-<td>18.1.9</td>
-<td>Dylan Baker</td>
-<td>Last planned 18.1.x release</td>
-</tr>
-<tr>
 <td rowspan="4">18.2</td>
 <td>2018-10-03</td>
 <td>18.2.2</td>

docs/relnotes.html

@@ -21,6 +21,7 @@ The release notes summarize what's new or changed in each Mesa release.
 </p>
 
 <ul>
+<li><a href="relnotes/18.1.9.html">18.1.9 release notes</a>
 <li><a href="relnotes/18.2.1.html">18.2.1 release notes</a>
 <li><a href="relnotes/18.2.0.html">18.2.0 release notes</a>
 <li><a href="relnotes/18.1.8.html">18.1.8 release notes</a>