When you start recording using SDL pulseaudio driver the client sends
all audio captured while not recording. 240 milliseconds of audio is
sent each frame until the capture buffer is empty. This is a problem for
privacy and causes confusing to debug VoIP playback issues on other
clients connected to server and when playing back demos.
The version check is required for supporting macOS PPC with SDL 2.0.1
and Travis-CI (Ubuntu Trusty) with SDL 2.0.2.
The client now requires SDL 2.0.5 runtime if compiled against SDL 2.0.5
or newer.
This is a little bit of future-proofing, but also gives us a little more
flexibility in general; now we can add in the cvars to open a specific
device, etc, that the OpenAL codepath does.
In SDL2, the initialized subsystems are referenced counted, so it's safe to
initialize them twice, and it makes the SDL_QuitSubSystem during our shutdown
correctly decrement the count. Before (as a probably-harmless bug), it would
not increment the refcount if the subsystem was already initialized, causing
problems when it decremented it later.
