reviewed and cleaned-up the CSS 3D GPU-accelerated code routines (now off by default as it was creating too many nasty side effects, and the native WebView can be tweaked so that its rendering surface compositing works well with the iframes inside reader.html)
Merge pull request #134 from readium/feature/webviewRenderingBug

review and clean-up of the CSS 3D GPU-accelerated code routines (now off by default)