Added documentation on how to configure logging

Added documentation on how to configure java.util.logging programmtically and via a properties file

This PR relies on PR #64 
I don't think we need to defend our decision in this first paragraph, we can just say:

> In version TBD we migrated from our own logging code to using [java.util.logging](http://docs.oracle.com/javase/7/docs/api/index.html?java/util/logging/) for logging. This document explains how to configure java.util.logging for android-sync.