Enable SDL audio capture for SDL 2.0.5 and newer

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.

code/sys/sys_local.h

@@ -23,10 +23,22 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "../qcommon/q_shared.h"
 #include "../qcommon/qcommon.h"
 
+#ifndef DEDICATED
+#ifdef USE_LOCAL_HEADERS
+#	include "SDL_version.h"
+#else
+#	include <SDL_version.h>
+#endif
+
 // Require a minimum version of SDL
 #define MINSDL_MAJOR 2
 #define MINSDL_MINOR 0
+#if SDL_VERSION_ATLEAST( 2, 0, 5 )
+#define MINSDL_PATCH 5
+#else
 #define MINSDL_PATCH 0
+#endif
+#endif
 
 // Console
 void CON_Shutdown( void );