Remove ic_launcher images

[nhaarman]

The library contains ic_launcher resources, with the default Android icon (For example https://github.com/rey5137/material/blob/master/lib/src/main/res/drawable-hdpi/ic_launcher.png). Since ic_launcher is the common name for the launcher icon, this may lead into trouble for apps using your library.

In my case, I didn't have the mdpi launcher icon, which led to your Android ic_launcher icon being shown on mdpi devices, instead of scaling down my hdpi version.

[rey5137]

I removed it in next version.