Added email icon to posts list sent status

refs https://github.com/TryGhost/Team/issues/954

- The email icon is signalling there was a newsletter sent with the post and allows to identify the "email only" posts easier

ghost/admin/app/components/gh-posts-list-item.hbs

@@ -68,12 +68,15 @@
             {{#if @post.isPublished}}
             <span class="gh-content-status-published nowrap">
                 Published
+                {{#if @post.hasEmail}}
+                <span>{{svg-jar "email-unread"}}</span>
+                {{/if}}
             </span>
             {{/if}}
 
             {{#if @post.isSent}}
-            <span class="gh-content-status-published nowrap">
-                Sent
+            <span class="gh-content-status-emailed nowrap">
+                <span>{{svg-jar "email-unread"}}</span>
             </span>
             {{/if}}
         </div>

ghost/admin/app/models/post.js

@@ -158,6 +158,9 @@ export default Model.extend(Comparable, ValidationEngine, {
     isPost: equal('displayName', 'post'),
     isPage: equal('displayName', 'page'),
 
+    hasEmail: computed('email', 'emailOnly', function () {
+        return this.email !== null || this.emailOnly;
+    }),
     willEmail: computed('emailRecipientFilter', function () {
         return this.emailRecipientFilter !== null;
     }),

ghost/admin/app/styles/layouts/content.css

@@ -273,14 +273,16 @@
 .gh-content-status-emailed {
     display: inline-block;
     margin: 0px 6px;
-    background: var(--lightgrey);
-    padding-right: 5px;
+    color: var(--midgrey);
+    background: var(--whitegrey);
     border-radius: 3px;
 }
 
-.gh-content-status-emailed svg {
+.gh-content-status-emailed svg,
+.gh-content-status-published svg {
     width: 12px;
     height: 12px;
+    fill: var(--midgrey);
 }
 
 .gh-content-status-emailed.error {