Follow changes by bug 755724 (files and directories are layouted in new places)

- [755724 – (metro-build) Split platform and app resources up so that they can be loaded individually](https://bugzilla.mozilla.org/show_bug.cgi?id=755724)
- [Moz-Fx: Firefoxのフォルダ構成](http://mozfx.blogspot.jp/2013/02/firefox.html)

On Firefox 21, some files and directories are moved under "browser".
