Router pics (#37)

* add a padding to sidebar for better use on mobile devices

* allow other things as text in attributeEntry

Now it is possible to use pictures and other stuff in this function

* Show Router-Pic with double fallback

3 Möglichkeiten
1. in config wird externe Quelle angegeben
2. wenn nicht wird in ./nodes/ geseucht
3. ansonsten Knotenname + Knotenname in erster Zeile

extern via:
cdn

"hwImg": [
  { "thumbnail": "https://cdn.rawgit.com/Moorviper/meshviewer_hwpics/master/nodes/{MODELHASH}.svg",
    "caption": "Knoten {MODELHASH}"
  }
 ]

aktueller nicht cdn:
"hwImg": [
  { "thumbnail": "https://rawgit.com/Moorviper/meshviewer_hwpics/master/nodes/{MODELHASH}.svg",
    "caption": "Knoten {MODELHASH}"
  }
 ]

scss/_sidebar.scss

@@ -0,0 +1,40 @@
+.nodeheader {
+    width: 90%;
+    position: relative;
+    z-index: 2;
+}
+
+.nodeheader img {
+    width: 30%;
+    max-height: 180px;
+    margin: auto;
+    text-align: center;
+    max-width: 128px;
+    display: block;
+    z-index: 2;
+}
+.nodeheader img .none{
+    display: none;
+}
+
+.nodeheader span {
+    background-color: silver;
+    background-color: hsla(0, 0%, 100%, 0.5);
+    position: absolute;
+    bottom: 0;
+    width: 100%;
+    line-height: 1.5em;
+    text-align: center;
+    color: black;
+    font-weight: bold;
+    font-size: large;
+    z-index: 2;
+    white-space: nowrap;
+    overflow: hidden;
+    text-overflow: ellipsis;
+}
+
+.limit {
+    min-height: 1px;
+    max-height: 1px;
+}