game_engine. Initialize SLES audio source player object.

Add audio source initialization error exception.
Change SLES audio source constructor to get SLES engine and sink.
Add initialize SLES player private initialzation method.
Update SLES engine to create source to pass the SLES engine and listener SLES sink to the SLES source.
Add TODO on passing audio source creation parameters.
game_engine. Initialize SLES audio source interfaces.

Add play, buffer queue, and volume interface fields to SLES source.
Add initialize player interfaces private method to SLES audio source - called from constructor.
game_engine. Add SLES audio source cleanup.
game_engine. Fixes to SLES audio source instrumentation.
game_engine. Update audio source buffer methods.

Replace add buffer with set buffer.
Replace remove buffer with clear buffer.
Instead of raw buffer, change the interface to use shared pointers to os memory_buffer.
Purpose of the chnages is to make the interface easier to use and to manage buffers. The client is responsible for all buffer management.
game_engine. Implement SLES audio source buffer management.

Implement SLES audio source set buffer.
Implement SLES audio source clear buffer.
Add buffers field to SLES audio source.
game_engine. Change OS memory buffer to copyable.