Client report moved to inside an iframe

In response to https://github.com/meteor-velocity/html-reporter/issues/27 (Overlay is overly sensitive to body page styles)

I have moved the client report into an iframe. This is necessary to fully isolate the CSS.

So far I haven't done anything to make the styles work inside the iframe yet. 
Maybe easiest to read CSS contents into a `<style>` tag using `Asset.getText`? 
Otherwise, I don't know how to link to the asset without [this grep hack](https://github.com/numtel/phantomjs-persistent-server/blob/d68da707f4de54a529120d457eaba195555b4e60/assetKey.js) I employed in a package of mine.
Both of these paths bypass the less preprocessor though...

Discussion?
![screenshot from 2014-10-22 02 52 32](https://cloud.githubusercontent.com/assets/518698/4734236/62856948-59d1-11e4-8efd-bfc7dbf2eeb3.png)