Cleaning in ICallable + changed fingerprint to plain char array to allow for dead object examination + additional check in FetchContext callback to avoid the unexplained rogue callbacks I have seen + protection in LoaderStateMachine::HandleSuccessMessage in case things go wrong anyway

#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