Fix audio not playing beyond 4 seconds on OS X.

The OS X implementation of alGetSourcei alway returns 0 for AL_BUFFER
if the input source is streaming.
Merge pull request #134 from DeVaukz/develop

Fix audio not playing beyond 4 seconds under OS X.
Merge branch 'develop' of https://github.com/adam4813/Sigma into OpenAL
Updated a debug condition