CSS and layout fixes for image uploader

closes #1673
- dropzone icon doesn't appear when filestorage is false
- proper cursor and no selection on icon
- cleaned up some sass

ghost/admin/assets/lib/uploader.js

@@ -193,7 +193,10 @@
                     }
                 });
 
+                // Only show the toggle icon if there is a dropzone mode to go back to
+                if (settings.fileStorage !== false) {
                     $dropzone.append('<a class="image-upload" title="Add image"><span class="hidden">Upload</span></a>');
+                }
 
                 $dropzone.find('a.image-upload').on('click', function () {
                     $dropzone.find('.js-url').remove();

ghost/admin/assets/sass/modules/global.scss

@@ -1333,7 +1333,6 @@ main {
 
     .image-url,
     .image-upload {
-        @include icon($i-link, 12px);
         line-height: 12px;
         padding: 10px;
         display: block;
@@ -1342,7 +1341,21 @@ main {
         left: 0;
         color: $brown;
         text-decoration: none;
+        @include user-select(none);
+
+        &:hover {
+          cursor: pointer;
         }
+    }
+
+    .image-webcam {
+      @include icon($i-camera, 12px);
+    }
+
+    .image-url {
+      @include icon($i-link, 12px);
+    }
+
     .image-upload {
       @include icon($i-image, 12px);
     }
@@ -1358,17 +1371,7 @@ main {
       margin: 0 0 0 10px;
     }
 
-    .image-webcam {
-        @include icon($i-camera, 12px);
-        line-height: 12px;
-        padding: 10px;
-        display: block;
-        position: absolute;
-        bottom: 0;
-        right: 0;
-        color: $brown;
-        text-decoration: none;
-    }
+
 
     input {
         &.main{