ofOpenALSoundPlayer: stop/pause for streams not working

[mnstri]

Stop and pause do not work for files that are being streamed. There is already a fix for this: openframeworks@cd2f807

This fix also works on the Raspberry Pi.

[bakercp]

We are going to be merging this into the core in the coming days / week. So that should be solved then. We can keep it open as a reminder to test it after that.