Blender Git Loki

Fix for slow starting of Blender.

This was caused by calling sound_init_audio() at startup. In situations
where Blender was first started, or when other applications used memory,
this could take 5-15 seconds.
I have moved the init call to 'start ketsji', and made sure any call
to an audio play routine will invoke an init as well.

Tested with engine and loading/play sound in F10 menu. I don't know how
the BlenderPlayer handles it... should be investigated.

Result: At OSX Blender starts in a second again! :)