Modified code completion for better tabbing, and removal of need to backspace and re-enter '(' to get code completion hints.

scene/gui/text_edit.cpp

@@ -2040,6 +2040,7 @@ void TextEdit::_gui_input(const Ref<InputEvent> &p_gui_input) {
 
 						_confirm_completion();
 						accept_event();
+						emit_signal("request_completion");
 						return;
 					}