1278: Improve image handling esp. when not available

Task-Url: https://pm.winseda.de/issues/1278

css/application-gs.css

@@ -357,6 +357,11 @@
   -webkit-background-clip: padding-box;
   background-clip: padding-box;
   background: url("../../img/page_icon_faded.png") center 20px no-repeat; }
+  #item-detail-container #item-images #carousel-item-images .carousel-inner .preview-image-label {
+    text-align: center; }
+  #item-detail-container #item-images .carousel-control-next,
+  #item-detail-container #item-images .carousel-control-prev {
+    border: none; }
   #item-detail-container #item-images .search-result-image-tmb {
     height: 135px;
     width: 135px; }