Handle ANSI Escapes in Docker Logs

[vifino]

Sen currently does not handle ANSI Escapes in docker logs.

It neither strips them nor does it interpret them.

I would definitly like to see sen supporting ANSI Escapes and interpreting them, allowing color in docker logs to be properly shown.

[TomasTomecek]

Thanks for report. I agree this is needed. (I often do docker logs instead of using sen).

I created upstream issue in the toolkit sen is using b/c I'm not sure what's the best of way of doing this.

[TomasTomecek]

I spent some time on this and gotta say it's really complicated - ANSI escape sequences are pretty rich.

I decided to split this into two phases:

1. clear the text from sequences, ignore all of them -- this is done
2. keep coloring -- deferring later