LightManager::sgSpecialLights not initialized

The sgSpecialLights array in LightManager isn't initialized properly and can contain garbage at certain times during initialization. The fix is to move the constructor from the header to the source file...

LightManager::LightManager()
{
   dMemset(&sgSpecialLights, 0, sizeof(sgSpecialLights)); // TOM: Clear the array.
   sgInit();
}