+ Notice that there can be more than one event loop at any given moment, e.g.
+ an event handler called from the main loop can show a modal dialog, which
+ starts its own loop resulting in two nested loops, with the modal dialog
+ being the active one (its IsRunning() returns @true). And a handler for a
+ button inside the modal dialog can, of course, create another modal dialog
+ with its own event loop and so on. So in general event loops form a stack
+ and only the event loop at the top of the stack is considered to be active.
+ It is also the only loop that can be directly asked to terminate by calling
+ Exit() (which is done by wxDialog::EndModal()), an outer event loop can't
+ be stopped while an inner one is still running. It is however possible to
+ ask an outer event loop to terminate as soon as all its nested loops exit
+ and the control returns back to it by using ScheduleExit().
+