By default Evt will print a warning if more than 25 handlers are added. This is a useful default that helps finding memory leaks. Not all events should be limited to 25 handlers. The evt.setMaxHandlers() method allows the limit to be modified for this specific Evt instance. ( Use the static method Evt.setDefaultMaxHandlers() to change this limit globally.
The value can be set to Infinity (or 0) to indicate an unlimited number of listeners.
Returns a reference to the Evt, so that calls can be chained.