A few related changes:

A few related changes:

* Change the encode_sample routine to simply return normal memchunks allocated from the mempool.
* unref the memchunks returned from encode_sample when we are done with them.
* Create an encoded 'silence' sample and play this at all times to prevent hangup and to 'hog' the airtunes device

This now works and can be used as a regular sink albeit with a constant latency of about 8 seconds :s

git-svn-id: file:///home/lennart/svn/public/pulseaudio/branches/coling@2485 fefdeb5f-60dc-0310-8127-8f9354f1896f