Edit and create timesheet records in modal (#603)

- added loading indicator for datatables
- fix multiple reloads of datatable content

assets/sass/datatable.scss

@@ -5,6 +5,43 @@
  * file that was distributed with this source code.
  */
 
+/* Loading indicator: overwritten from AdminLTE for positioning and supporting fas classes */
+.box .overlay > .fas,
+section.content .overlay > .fas,
+.overlay-wrapper .overlay > .fas {
+    position: absolute;
+    top: 50vh;
+    left: 50vw;
+    margin-left: -15px;
+    margin-top: -15px;
+    color: #000;
+    font-size: 30px;
+}
+
+.box > .overlay,
+.overlay-wrapper > .overlay,
+section.content > .overlay,
+.box > .loading-img,
+.overlay-wrapper > .loading-img {
+    position: absolute;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+}
+.box .overlay,
+section.content .overlay,
+.overlay-wrapper .overlay {
+    z-index: 50;
+    background: rgba(255, 255, 255, 0.7);
+    border-radius: 3px;
+}
+.box .overlay.dark,
+section.content .overlay.dark,
+.overlay-wrapper .overlay.dark {
+    background: rgba(0, 0, 0, 0.5);
+}
+
 /*
 dataTables.bootstrap.css
 */
@@ -244,6 +281,8 @@ table.dataTable {
         }
         .label {
             font-size: 85%;
+            font-weight: 500;
+            padding: .3em .6em .3em;
         }
     }
 }