ECMAScript fixups

I removed the external script elements from test-to-jsunit.js, eliminated debugging alerts and fixed a function name messup in the Mozilla loading implementation in DOMTestCase.js, and removed mozsafe from the tests since Mozilla 0.9.7 no longer crashes on bogus string offsets.

With these changes and integrating the JSUnit changes I just sent, hopefully Dimitris can finally run the ECMAScript suite on his Mac.

I don't know what the performance would be, but it should now be possible to run the ECMAScript suite on the web.