Separating example code from the library

Hi,

Thanks for the nice library, it does exactly what I was looking for! :smile: 

One thing that was lacking for me was the separation between "example" and "library" code. So I forked your code and made the split so it can be better used as a library.

I've also changed the project type from "android" to "android-library" for the "library" project.

I hope you can incorporate these changes.
Cheers,

Wijnand

PS: As a bonus you no longer need to filter files when you create the Jar.