Add missing prototype, ugh

src/hardware/hw_main.h

@@ -57,6 +57,7 @@ UINT8 *HWR_GetScreenshot(void);
 boolean HWR_Screenshot(const char *pathname);
 
 void HWR_AddCommands(void);
+void HWR_AddSessionCommands(void);
 void HWR_CorrectSWTricks(void);
 void transform(float *cx, float *cy, float *cz);
 FBITFIELD HWR_TranstableToAlpha(INT32 transtablenum, FSurfaceInfo *pSurf);