Better error log in fetch failure callback + timeout 600sec in OrthancRestApiCommand + guard against dead controller access in PanSceneTracker + relaxed DicomStructureSet AddReferenceSlice method to accept extraneous adds of the same slice (while trying to understand how it happens in the first place)

#pragma once

#if ORTHANC_ENABLE_WASM == 1
// https://emscripten.org/docs/optimizing/Optimizing-WebGL.html
#  define ORTHANC_STONE_OPENGL_SHADER_VERSION_DIRECTIVE "precision mediump float;\n"
#else
#  define ORTHANC_STONE_OPENGL_SHADER_VERSION_DIRECTIVE "#version 110\n"
#endif