message: fix rendertarget sample app
  we can't use a projection with infinite far as a custom
  projection matrix, because this is not suited for culling.
  recently a new version of setCustomProjection was added which allows
  to specify both the rendering and culling projections.
diff: @@ -295,7 +295,7 @@ int main(int argc, char** argv) {
  .receiveShadows(true)
  .castShadows(false)
  .build(*engine, app.reflectedMonkey);
  - setReflectionMode(app, ReflectionMode::CAMERA);
  + setReflectionMode(app, app.mode);
  // Add light source to both scenes.
  // NOTE: this is slightly wrong when the reflection mode is RENDERABLES.
  @@ -356,15 +356,18 @@ int main(int argc, char** argv) {
  const mat4f reflection = reflectionMatrix(planeEquation);
  // Apply the reflection matrix to either the renderable or the camera, depending on mode.
  + Camera const& camera = view->getCamera();
  + const auto model = camera.getModelMatrix();
  + const auto renderingProjection = camera.getProjectionMatrix();
  + const auto cullingProjection = camera.getCullingProjectionMatrix();
  + app.offscreenCamera->setCustomProjection(renderingProjection, cullingProjection, camera.getNear(), camera.getCullingFar());
  switch (app.mode) {
  case ReflectionMode::RENDERABLES:
  tcm.setTransform(tcm.getInstance(app.reflectedMonkey), reflection * xform);
  - app.offscreenCamera->setModelMatrix(view->getCamera().getModelMatrix());
  - app.offscreenCamera->setCustomProjection(view->getCamera().getProjectionMatrix(), 0.1, 100.0);
  + app.offscreenCamera->setModelMatrix(model);
  break;
  case ReflectionMode::CAMERA:
  - app.offscreenCamera->setModelMatrix(reflection * view->getCamera().getModelMatrix());
  - app.offscreenCamera->setCustomProjection(view->getCamera().getProjectionMatrix(), 0.1, 100.0);
  + app.offscreenCamera->setModelMatrix(reflection * model);
  break;
  }
  });
  