Update min OS requirement for snapshot-168 to macOS 10.14

The latest build broke 10.13 due to a build issue linking against newer
symbols. Simply disable this version for older versions of macOS for now
before snapshot-169 fixes this.

Also, include snapshot-166 in the appcast so people running macOS 10.13
or below will still be able to update to it successfully and Sparkle
will show that their MacVim is up to date instead of an error message.

Author: ychin

appcast/latest.xml

@@ -100,7 +100,7 @@
 
       ]]></description>
       <pubDate>Fri, 11 Dec 2020 22:00:00 -0800</pubDate>
-      <sparkle:minimumSystemVersion>10.9</sparkle:minimumSystemVersion>
+      <sparkle:minimumSystemVersion>10.14</sparkle:minimumSystemVersion>
       <enclosure type="application/octet-stream"
         url="https://github.com/macvim-dev/macvim/releases/download/snapshot-168/MacVim.dmg"
         sparkle:version="168"
@@ -118,5 +118,68 @@
           />
       </sparkle:deltas>
     </item>
+    <item>
+      <title>MacVim snapshot-166</title>
+      <description><![CDATA[
+<style>
+:root { supported-color-schemes: light dark; color-scheme: light dark; }
+</style>
+<p>Updated to Vim 8.2.1719.</p>
+
+<h1 id="features">Features</h1>
+
+<h2 id="touch-bar-improvements">Touch Bar improvements</h2>
+
+<p>Touch Bar now supports submenus, and allows mixed icon/text displays using <code>tmenu</code>. When in edit modes (e.g. insert), it will also display an emoji picker as well. See <code>:help touchbar</code> for documentation. <a href="https://github.com/macvim-dev/macvim/issues/1084">#1084</a></p>
+
+<p><img width="640" src="https://user-images.githubusercontent.com/1217449/93730988-f2bb4900-fb7f-11ea-9433-4a15187a4af1.png" alt="emoji picker / submenu / icons with labels" title="Example configuration with emoji picker / submenu / icons with labels" /></p>
+<p><img width="640" src="https://user-images.githubusercontent.com/1217449/93730989-f77ffd00-fb7f-11ea-9e44-0dfc36d146f2.png" alt="inside submenu" title="Example of inside a submenu" /></p>
+<p><img width="640" src="https://user-images.githubusercontent.com/1217449/93731159-b63c1d00-fb80-11ea-84a1-77c57d818452.png" alt="activated emoji picker" title="Activated emoji picker" /></p>
+
+<h1 id="fixes">Fixes</h1>
+
+<ul>
+  <li>Window menu no longer shows duplicate “Enter Full Screen” or “Tile Window to Left of Screen” entries whenever the user switches among different MacVim windows. <a href="https://github.com/macvim-dev/macvim/issues/566">#566</a> <a href="https://github.com/macvim-dev/macvim/issues/992">#992</a></li>
+  <li>Fix issue where going to full screen mode when titlebar appearance is set to “hidden” would result in lost focus of the window. <a href="https://github.com/macvim-dev/macvim/issues/1078">#1078</a></li>
+  <li>The password dialog box when using <code>:!sudo</code> or other commands that require password entry (<code>macvim-askpass</code>) will no longer focus on Finder, and will keep the focus on MacVim. <a href="https://github.com/macvim-dev/macvim/issues/1091">#1091</a></li>
+  <li>Fix minor wrong tooltip in the “Appearance” preference pane. <a href="https://github.com/macvim-dev/macvim/issues/1087">#1087</a></li>
+  <li>“General” preference pane will now be correctly sized when Sparkle updater is disabled (e.g. Homebrew builds). <a href="https://github.com/macvim-dev/macvim/issues/1089">#1089</a></li>
+  <li>Misc issues were fixed by Vim upstream, e.g. <code>vimgrep</code> causing a crash, and odd behaviors with using Shift-O on the first line. <a href="https://github.com/macvim-dev/macvim/issues/1082">#1082</a> <a href="https://github.com/macvim-dev/macvim/issues/1083">#1083</a></li>
+</ul>
+
+<h1 id="compatibility">Compatibility</h1>
+
+<p>Requires macOS 10.9 or above.</p>
+
+<p>Script interfaces have compatibility with these versions:</p>
+
+<ul>
+  <li>Lua 5.3</li>
+  <li>Perl 5.18</li>
+  <li>Python2 2.7</li>
+  <li>Python3 3.8</li>
+  <li>Ruby 2.7</li>
+</ul>
+
+      ]]></description>
+      <pubDate>Sun, 20 Sep 2020 21:00:00 -0700</pubDate>
+      <sparkle:minimumSystemVersion>10.9</sparkle:minimumSystemVersion>
+      <enclosure type="application/octet-stream"
+        url="https://github.com/macvim-dev/macvim/releases/download/snapshot-166/MacVim.dmg"
+        sparkle:version="166"
+        sparkle:shortVersionString="8.2.1719"
+        sparkle:dsaSignature="MC0CFDvTjlB/c8USlTUjocXm5Q/nvm/FAhUAtRDNxUt1Q8KFpabseqbZuOhuMB0="
+        sparkle:edSignature="3cdukqFfh5kERiAiBbJgVC+4r4tOMWJIHMzTYGf2scqJgyR5HtEJf2oBvJpoxzidSnliSdo35lApQm8rXjLcDw==" length="20105287"
+        />
+      <sparkle:deltas>
+        <enclosure type="application/octet-stream"
+          url="https://github.com/macvim-dev/macvim/releases/download/snapshot-166/165_to_166.delta"
+          sparkle:version="166"
+          sparkle:deltaFrom="165"
+          sparkle:dsaSignature="MC0CFQCCqpQbVg7eEhgq9q/R1xDg0v4ITgIUBFhHuEAeU7TwKJkm1CFfQGX8I1k="
+          sparkle:edSignature="afRPeC51wAdnV7wZMT+kgw70AlmnH+Zy831RGM5ffm76kmFPbzRtkbqRy+nyVDNMqUEmrD5wSwdpQ3J6CSxACw==" length="754048"
+          />
+      </sparkle:deltas>
+    </item>
   </channel>
 </rss>