Add (untested) Steam Link video decoding/rendering

config.tests/SLVideo/SLVideo.pro

@@ -0,0 +1,3 @@
+SOURCES = main.cpp
+LIBS += -lSLVideo
+

config.tests/SLVideo/main.cpp

@@ -0,0 +1,7 @@
+#include <SLVideo.h>
+
+int main()
+{
+    SLVideo_CreateContext();
+    return 0;
+}