Fix: Event methods automatic addition of .dt namespace was greedy

* Need to ensure that the `.dt` namespace is still added to external
  namespaces such as `.dtr`.

.datatables-commit-sync

@@ -1 +1 @@
-ad3a2ea74090ef0721f2e74f2e14ea883739c05c
+8f6df2b9f072694f09dbf1951d7cf6d206218c48

media/js/jquery.dataTables.js

@@ -8628,7 +8628,7 @@
 			var args = Array.prototype.slice.call(arguments);
 	
 			// Add the `dt` namespace automatically if it isn't already present
-			if ( args[0].indexOf( '.dt' ) === -1 ) {
+			if ( ! args[0].match(/\.dt\b/) ) {
 				args[0] += '.dt';
 			}