Ladebalken bei Layer-Aktivierung + Ortsnamen-Rendering verbessert

- Animierter Ladebalken unter jedem Layer-Toggle bei Datenabruf
- Status-Text (Lade Daten.../Fehler beim Laden)
- Fetch-Wrapper: nur 401 redirected zum Login, nicht 403
- Ortsnamen: minimumLevel, tileWidth/Height, LINEAR Texture-Filter
  fuer konsistente Schriftgroessen beim Laden

static/index.html

@@ -21,7 +21,7 @@
             opts.headers['Authorization'] = 'Bearer ' + localStorage.getItem('globe_token');
         }
         return _origFetch(url, opts).then(function(r) {
-            if (r.status === 401 || r.status === 403) { localStorage.removeItem('globe_token'); window.location.href = '/login'; }
+            if (r.status === 401) { localStorage.removeItem('globe_token'); window.location.href = '/login'; }
             return r;
         });
     };
@@ -52,24 +52,32 @@
                 <span class="layer-name">Flugverkehr</span>
                 <span class="layer-count" id="count-flights">-</span>
             </label>
+            <div class="layer-loading" id="loading-flights"></div>
+            <div class="layer-status" id="status-flights"></div>
             <label class="layer-toggle">
                 <input type="checkbox" id="layer-ships" checked>
                 <span class="layer-dot dot-ships"></span>
                 <span class="layer-name">Schiffsverkehr</span>
                 <span class="layer-count" id="count-ships">-</span>
             </label>
+            <div class="layer-loading" id="loading-ships"></div>
+            <div class="layer-status" id="status-ships"></div>
             <label class="layer-toggle">
                 <input type="checkbox" id="layer-quakes">
                 <span class="layer-dot dot-quakes"></span>
                 <span class="layer-name">Erdbeben</span>
                 <span class="layer-count" id="count-quakes">-</span>
             </label>
+            <div class="layer-loading" id="loading-quakes"></div>
+            <div class="layer-status" id="status-quakes"></div>
             <label class="layer-toggle">
                 <input type="checkbox" id="layer-gdelt">
                 <span class="layer-dot dot-gdelt"></span>
                 <span class="layer-name">Nachrichten</span>
                 <span class="layer-count" id="count-gdelt">-</span>
             </label>
+            <div class="layer-loading" id="loading-gdelt"></div>
+            <div class="layer-status" id="status-gdelt"></div>
         </div>
         <div class="panel-divider"></div>
         <div class="panel-section">