[new mw-js api] Event handlers returning false no longer silence output

https://projects.sucs.org/projects/mw/wiki/JavaScript says "If any function bound to handle an event returns 'false' then you get the equivalent of 'output off' in mwscript (the default output of mw is supressed allowing your scripts to produce their own output to events)"

How to reproduce:

$ cat .mwrc
include mw-script/newmwjs-test.js

$ cat mw-script/newmwjs-test.js
function testevh(event){
         mw.print(JSON.stringify(event));
         return false;
}

mw.onevent.push(testevh);

mw.print("DEBUG: mw.onevent has: " + mw.onevent.toString());