Support for Stream as input

[bblanchon]

Copy the content of the stream in the JsonBuffer
Ideally, remove the spaces to use less memory.

[Diaoul]

I'm reading JSON from Serial and I'd like to avoid an extra buffer. Would that work for me?

[bblanchon]

@Diaoul Yes, the input will be copied in the JsonBuffer automatically.

[bblanchon]

Feature available in release 5.8.0

[sticilface]

Double thumbs up for this! big help :) thanks!!!

[bblanchon]

Thanks @sticilface, it's been quite a challenge.

It's much more efficient than using Stream::readBytes() as before as the JsonBuffer will duplicate the minimal amount of data, thus saving a lot of memory if the input JSON is indented.

The ArduinoJson Assistant has been updated to tell the number of bytes that are required for the duplication.