Bump DataTables from 1.13.2 to 2.1.8

The existing features seem to work fine. It is more maintainable and
easier to develop using the v2 version.

formats/datatables/resources/ext.srf.formats.datatables.css

@@ -1,27 +1,25 @@
 
-.srf-datatable .srf-datatable-left {
+.dt-filter {
 	float: left;
 }
 
-.srf-datatable .srf-datatable-right {
-	float: right;
+.dt-length {
+	float: right;	
 }
 
-
-.srf-datatable .dataTables_filter {
+.srf-datatable .srf-datatable-left {
 	float: left;
-
 }
 
-.srf-datatable .dataTables_length {
-	float: right;	
+.srf-datatable .srf-datatable-right {
+	float: right;
 }
 
 .srf-datatable .dt-buttons {
 	margin-right: 0.334em;
 }
 
-.srf-datatable .dataTables_filter {
+.srf-datatable .dt-filter {
 	margin-right: 0.334em;
 }
 
@@ -35,14 +33,14 @@
 	right: 8px;
 }
 
-div.dataTables_processing {
+div.dt-processing {
 	/* background: white; */
 	/* box-shadow: 0px 2px 18px 0px rgba(0,0,0,0.12); */
 	z-index: 1000;
 	position: sticky !important;
 }
 
-div.dataTables_processing>div:last-child>div {
+div.dt-processing > div:last-child > div {
 	background: rgb(13,110,253);
 }
 

formats/datatables/resources/ext.srf.formats.datatables.js

@@ -715,14 +715,6 @@
 				};
 
 				conf = $.extend(conf, {
-					// *** attention! deferLoading when used in conjunction with
-					// ajax, expects only the first page of data, if the preloaded
-					// data contain more rows, datatables will show a wrong rows
-					// counter. For this reason we renounce to use deferRender, and
-					// instead we use the following hack: the Ajax function returns
-					// the preloaded data as long they are available for the requested
-					// slice, and then it uses an ajax call for not available data.
-					// deferLoading: table.data("count"),
 					processing: true,
 					serverSide: true,
 					ajax: function (datatableData, callback, settings) {