Add cut or delete command shift+delete

lib/ace/commands/default_commands.js

@@ -404,6 +404,20 @@ exports.commands = [{
     ),
     exec: function(editor) { editor.remove("left"); },
     multiSelectAction: "forEach"
+}, {
+    name: "cut_or_delete",
+    bindKey: bindKey(
+        "Shift-Delete",
+        "Shift-Delete"
+    ),
+    exec: function(editor) { 
+        if( editor.selection.isEmpty() ){
+            editor.remove("left");
+        }else{
+            return false;
+        }
+    },
+    multiSelectAction: "forEach"
 }, {
     name: "removetolinestart",
     bindKey: bindKey("Alt-Backspace", "Command-Backspace"),