Update Oasis.js to support more browsers.

Use of MessageChannel.js.
Fix race condition in test

The render event is asynchronous
Add support for Firefox

Fixes processCSS for Firefox
resetCSS insert style element correctly for Firefox
Make test compatible for Firefox
Make HeightService compatible with Firefox
Add support for Safari
Merge pull request #34 from tildeio/message_channel

Update Oasis.js for browser support