Create a GtkButton with text

Property definitions

gtk $ GtkButton :: with_label
	# Create a GtkButton with text
	new with_label(text: String) import String.to_cstring `{
		return (GtkButton *)gtk_button_new_with_label(String_to_cstring(text));
	`}
lib/gtk/v3_4/gtk_core.nit:797,2--800,3