intents: Add a java class for listening to intent broadcasts
intents: hook up a JNI_OnLoad for finding our java functions

This should be extended to do lots more, so that we can quickly add java code
and access it from native, without the mess that is jni.
intents: add the very beginnings of an intents class

Implemented as a singleton, this will eventually have functions for setting up
receivers, callbacks, etc. Also, our broadcasting can move into here, to clean
up some of the mess in XBMCApp.
intents: Hook up our intents listener

For now, all it does is prints to the log
intents: add a sample listener for sdcard insert events
Merge pull request #2276 from theuni/intents

Beginning of Android intents handling