Implement XML.prototype.replace()
Merge pull request #540 from artcompiler/e4x

Implement XML.prototype.replace()
Set level and index on root.
Merge pull request #541 from tobeytailor/timeline

Fix issue #523.
First cut of the JavaScript->AS3 AVM1 migration
Merge pull request #551 from yurydelendik/as2-as3

First cut of the JavaScript->AS3 AVM1 migration
Fixes build-web