Streaming requirement

[nerdstein]

Currently, the encrypt stream supports block-level streaming (read file in, encrypt it, write it, close the stream). Some encryption algorithms have support for streaming, which will perform encryption incrementally as the file is read.

One approach is evaluating/copying the interface from halite.

Tasks:

• Ensure that the streaming requirement/suggestion is documented properly inside README.md + hook_requirements

[dawehner]

Added the issue in the encrypt issue queue to support us here: https://www.drupal.org/node/2738647

[dawehner]

Here is a start of a PR. Of course, the encrypt site of things first needs to be done, before we can continue here.

[TravisCarden]

I took a stab at this by converting to use stream filters in #23.

[TravisCarden]

This issue can be closed now, @nerdstein.