Fix streched favicon

The current favicon is vertically streched and violates branding
guidelines.  Reuse an existing, correct 32x32 PNG with transparency
instead of .ICO file.  This means that only IE version >= 11 are
supported.  Also use the modern format for specifying the favicon in
HTML.

CHANGELOG.md

@@ -21,6 +21,7 @@ All notable changes to this project will be documented in this file.
 - monkeysphere: Handle new uid format of gpg2.
 - monkeysphere: Fixed handling of unavailable imported domains.
 - minetest: Fixed showing status block and diagnostics.
+- Fix stretched favicon.
 
 ### Changed
 - dynamicdns, monkeysphere, transmission, upgrades: Use actions where

LICENSES

@@ -21,8 +21,6 @@ otherwise.
 - static/themes/default/img/apple-touch-icon-57px-precomposed.png :: -
 - static/themes/default/img/apple-touch-icon-72px-precomposed.png :: -
 - static/themes/default/img/apple-touch-icon.xcf :: -
-- static/themes/default/img/favicon-32px.ico :: -
-- static/themes/default/img/favicon.ico :: -
 - static/themes/default/img/freedombox-logo-200px.png :: -
 - static/themes/default/img/freedombox-logo-250px.png :: -
 - static/themes/default/img/freedombox-logo-32px.png :: -

plinth/templates/base.html

@@ -55,8 +55,9 @@
     </title>
   {% endblock %}
 
-  <!-- This is the traditional favicon. Size: 16x16 or 32x32, transparency is OK -->
-  <link rel="shortcut icon" href="{% static 'theme/img/favicon.ico' %}"/>
+  <!-- Favicon. Works with IE >= 11 and other GUI browsers -->
+  <link rel="icon" type="image/png"
+        href="{% static 'theme/img/freedombox-logo-32px.png' %}"/>
 
   <!-- The is the icon for iOS's Web Clip. Size: 57x57 for older iPhones, 72x72 for iPads, 114x114 for iPhone4
   - To prevent iOS from applying its styles to the icon name it thusly: apple-touch-icon-precomposed.png