Add Logger.

Add a convenient logging class which wraps around android Logger and
provides builtin methods to print class and method names and
automatically use that for the TAG.
Add IpAddress class.

Add a helper class for manipulating IP addresses in Android.
Add WifiBroadcastListener.

WifiBroadcastListener listens for a bunch of broadcast intents related
to Wifi and network connectivity changes.
Change yani-android -> yani in README.md
Hook up WifiBroadcastListener in YaniActivity.

Register/Unregister for the Broadcast intents in onResume/onPause.
Update the status fragment to display basic Wifi status.