Fix minification issues

* Move Gopher SVG from partial to image

In minification, Gopher gets wonked. This may also help build times with minification.

fixes #604

* Add margin around external link icon

In minification the links got pushed up against the nav item.

ref #604

* Move Hugo logo in footer/hero to image from partial

This may help with build-time when using minification.

* Move gopher image from site to theme static folder

I put this in the wrong directory in commit: 0e2f2f8f33588f826f26c3b3a581f1014a3d41ac

* Add alt tag copy to Gopher image

themes/gohugoioTheme/layouts/404.html

@@ -2,7 +2,7 @@
 <main class="cf pa5 pa4-l f4 tc center measure-wide lh-copy gray">
   <h1 class="f3 f2-ns">The page you're looking for doesn't exist. Perhaps you'd like to gopher something else? Sorry.</h1>
   <div class="h6">
-    {{ partial "svg/gopher-hero.svg" . }}
+    <img src="/images/gopher-hero.svg" alt="" class="h5">
   </div>
 
   {{ .Content }}

themes/gohugoioTheme/layouts/partials/hero.html

@@ -1,7 +1,7 @@
 <header class="bg-primary-color-dark ph4 tc" role="banner">
   <section class="center pb4 pb5-l ph4-l pt3 pt5-ns w-90 w-60-l">
     <div class="center w-100 w-50-ns">
-      {{ partial "svg/hugo-logo-wide.svg" . }}
+        <img src="/images/hugo-logo-wide.svg" alt="Hugo Logo">
     </div>
     {{ with .Site.Params.description }}
       <h2 class="f3 f1-l fw4 white-90 m0 lh-title pt2 pb3 pv0-ns">

themes/gohugoioTheme/layouts/partials/home-page-sections/installation.html

@@ -12,7 +12,7 @@
     <!-- RIGHT -->
     <div class="w-100 w-50-ns tc">
       <div class="h4">
-        {{ partial "svg/gopher-hero.svg" . }}
+        <img src="/images/gopher-hero.svg" alt="Hugo Gopher" class="h4">
       </div>
       <p class="f6 mid-gray m0 p0 pt3">Mac OS</p>
       <div class="code f6 bg-black light-green lh-copy pv3 ph3 br2 w-100 w-50-ns center mb2 tl">

themes/gohugoioTheme/layouts/partials/site-footer.html

@@ -7,7 +7,7 @@
           </div>
 
           <div class="center w4">
-            {{ partialCached "svg/hugo-logo-wide.svg" . }}
+            <img src="/images/hugo-logo-wide.svg" alt="Hugo Logo">
           </div>
 
           <ul class="center f6 list ma0 mv3 pa0 tc">

themes/gohugoioTheme/layouts/partials/site-nav.html

@@ -17,7 +17,9 @@
               {{/* using ".Post" from the menu system to determine if we should show an icon for external links */}}
             {{ $post_status := printf "%s" .Post }}
             {{ if eq $post_status "external" }}
-              {{ partial "svg/link-ext.svg" (dict "size" "10") }}
+              <span class="pl1">
+                {{ partial "svg/link-ext.svg" (dict "size" "10") }}
+              </span>
             {{ end }}
           </a>
         </li>