qstdweb provides a C++ API covering parts of the DOM API
useful for implementing Qt. This currently includes
ArrayBuffer, Blob, File, FileReader, and Uint8Array.
The implementation uses emscripten::val, which currently
able to acccess the DOM directly, once WebAssembly
gains such access.
This API should be easier to use than the string-and-casting
emscripten::val API. It is currently private, and can
be changed and extended as needed.
Reviewed-by: Lorn Potter <email@example.com>