HEIC support in Photo Admin (web app)

Browsers other than Safari cannot open HEIC photos, so Photo Admin loads these files, only
when it needs them, to decode HEIC photos on your own device:

  libheif.js, libheif.wasm   libheif-js 1.23.2, unmodified, from https://www.npmjs.com/package/libheif-js
                             (an Emscripten build of libheif 1.23.2 with the libde265 1.0.15 HEVC
                             decoder; decoding only)
  heic-worker.js             Photo Admin's own small worker that calls the library

Licence: GNU Lesser General Public License v3.0 (LICENSE.txt in this folder).

Source code:
  libheif-js 1.23.2   https://github.com/catdad-experiments/libheif-js/tree/v1.23.2
  libheif 1.23.2      https://github.com/strukturag/libheif/tree/v1.23.2
  libde265 1.0.15     https://github.com/strukturag/libde265/tree/v1.0.15

These are separate files: you may replace libheif.js and libheif.wasm with your own build of
the same interface.