Alexei

I would try adding tests, but, as of now, I can't even run tests on `master` without my changes. Looks like some of them fail due to CRLF issues as...

I have to increase JVM stack size to 4 MB as a workaround. Substitutions should not be parsed recursively.

This is still a huge issue for me. @havocp, do you think it can be easily fixed?

@dannylesnik, @ennru, as you were the main contributors, are there any plans to introduce proper backpressure and start supporting SDK 3 as 2.7 is no longer officially supported.

Possibly, a duplicate of #36