Factor out CameraEncoder, MicrophoneEncoder, and ScreenEncoder

[ronen]

[Another step towards #74]

Factored out CameraEncoder, MicrophoneEncoder, and ScreenEncoder

The only structural change is that previously there was a single bit destroy: Arc<AtomicBool> that would stop all encoding when it was set, but now each Encoder has its own. Previously the host.destroy() method would set that bit, but now it calls a .stop() method for each encoder.

Also:

• Moved the transforms from model/mod.rs into model/encode/transform.rs since they're only used in model/encode.

• Moved the wrappers from model/mod.rs into model/wrappers.rs just so that mod.rs isn't a mixed bag of submodule declarations and code definition.

[griffobeid]

Thanks for the contribution @ronen

I tested it out locally and it looks good to me! @darioalessandro can you take a look?

[darioalessandro]

Wow !!! this is great!! I love how you moved all the model out of the host!!

looking now

[darioalessandro]

I am sorry for taking this long! will review again by eod tomorrow July 9

[ronen]

I am sorry for taking this long! will review again by eod tomorrow July 9

July 9, but luckily you didn't specify a year :)

Just joking around, no rush.

[darioalessandro]

I am sorry for taking this long! will review again by eod tomorrow July 9

July 9, but luckily you didn't specify a year :)

Just joking around, no rush.

XD XD sorry mate, I am on it right now