Fix "Error: write after end" and removed @bug tags

[oxidase]

Issue

Fix the problem that is caused by too early close of a log stream at process exit, but https://nodejs.org/api/child_process.html#child_process_event_exit

Note that when the 'exit' event is triggered, child process stdio streams might still be open.

@daniel-j-h please could you check the change of log.end to log.write locally. I could reproduce it only with a release build and timeout 500ms.
/cc @springmeyer

Tasklist

• review
• adjust for for comments

Requirements / Relations

Supersedes #2934, if retest will be positive. Related to #2795

[springmeyer]

I've been unable to reproduce with either Debug or Release build and with either OS X or Linux. Also tried export CUCUMBER_TIMEOUT=500 && npm test. So, I think the idea next step here is to have @daniel-j-h - who appears to be able to reproduce easily - test this branch and merge if it solves his issue.