Use icons for all buttons

app/templates/inspect.hbs

@@ -3,16 +3,35 @@
   <nav class="actions">
     {{#if documentIsJSON}}
       <div class="button-group json-view">
-        <button disabled={{jsonShowTree}} class="{{if jsonShowTree "active"}}" {{action "showJsonTree"}}>tree view</button>
-        <button disabled={{jsonShowSource}} class="{{if jsonShowSource "active"}}" {{action "showJsonSource"}}>source</button>
+        {{#if metadataHidden}}
+          <button {{action "toggleMetadata"}}
+                  title="Show metadata">
+            {{partial "icons/arrow-from-right"}}
+          </button>
+        {{else}}
+          <button {{action "toggleMetadata"}}
+                  title="Hide metadata">
+            {{partial "icons/arrow-to-right"}}
+          </button>
+        {{/if}}
       </div>
       <div class="button-group json-view">
-        <button {{action "toggleMetadata"}}>
-          {{if metadataHidden "show" "hide"}} metadata
+        <button disabled={{jsonShowTree}}
+                class="{{if jsonShowTree "active"}}"
+                title="Tree view"
+                {{action "showJsonTree"}}>
+          {{partial "icons/list"}}
+        </button>
+        <button disabled={{jsonShowSource}}
+                class="{{if jsonShowSource "active"}}"
+                title="Show source"
+                {{action "showJsonSource"}}>
+          {{partial "icons/code"}}
         </button>
       </div>
     {{/if}}
-    <button class="delete" {{action "deleteItem"}}>delete</button>
+    <button class="delete" title="Delete"
+            {{action "deleteItem"}}>{{partial "icons/trash"}}</button>
   </nav>
 </header>