Bindings for Atomic Files

[kirillt]

This feature needs to be ported to Android:

• Write files atomically arklib#48
• #48: Atomic files arklib#50

We need to write nice Kotlin wrapper and unit tests, too.

[kirillt]

First, we need to define use-case for this.

Do apps really need to handle atomics?

Or should we hide them behind the API?

[kirillt]

Replaced by:

• JNI for fs-storage ark-android#90