Expose container streams

Refs #103 @5:00
Merge branch 'master' of https://github.com/IvyBits/JNML

Conflicts:
	src/main/java/tk/ivybits/javi/JPlay.java
	src/main/java/tk/ivybits/javi/media/Media.java
	src/main/java/tk/ivybits/javi/swing/SwingMediaPanel.java
Streaming improvements

* Make MediaStream implement Runnable instead of Thread
* Add missing documentation to event methods
Fix crash when either video or audio stream not present

Closes #108 @1h