Patch/remove label shadows

Actually I think shadowless history looks great! Thanks for having compile time option for that, but I think you should consider shadowless as default.

Here's how it look here together with PDF icons (see my other merge).

![shadowless labels](https://f.cloud.github.com/assets/103067/2055118/51bcb732-8ac0-11e3-9a46-bcffb6815bef.png)