initial backport of #6777 - mobile public pages - to stable5

Backport of #6777 to stable5

I still have problems with the UI on my android:

![screenshot_2014-02-13-12-22-07](https://f.cloud.github.com/assets/956847/2159417/d7f3af98-94a4-11e3-8c7d-86e57a2714d6.png)
![screenshot_2014-02-13-12-21-35](https://f.cloud.github.com/assets/956847/2159418/d7f4fa24-94a4-11e3-9884-5a6d73eba3ad.png)

@jancborchardt need CSS help!

@DeepDiver1975 do we need to backport the gallery view for public files to stable5 as well?