Merge branch 'master' into canary

layouts/partials/head/head.html

@@ -2,7 +2,7 @@
 <meta name='viewport' content='width=device-width, initial-scale=1'>
 
 {{- $description := partialCached "data/description" . .RelPermalink -}}
-<meta name='description' content='{{ $description }}'>
+<meta name='description' {{ printf "content=%q" $description | safeHTMLAttr }}>
 {{ with .Params.Keywords }}<meta name="keywords" content="{{ delimit . ", " }}">{{ end }}
 
 {{- $title := partial "data/title" . -}}
@@ -23,7 +23,7 @@
     {{ if $favicon }}
         <link rel="shortcut icon" href="{{ $favicon.RelPermalink }}" />
     {{ else }}
-        {{ errorf "Failed loading favicon from %q" . }}
+        <link rel="shortcut icon" href="{{ . | relURL }}" />
     {{ end }}
 {{ end }}