[Openal] Performance testing

[Chris Robinson]

I think the best way to compare performance is to use a profiler. Something 
like oprofile can work without any special setting up for the app (though it 
requires some setting up for the system/kernel). Another is gprof.. that 
requires building lib as static and compiling+linking the lib and app 
with -pg, but doesn't require any system/kernel changes. Note that OpenAL 
Soft doesn't provide a static lib normally, but you can edit CMakeLists.txt 
to use STATIC instead of SHARED for the ADD_LIBRARY call.