* ignore null array items in incoming webhooks / command responses
* consolidate code, process announcements in command response as well
* make a bit more idiomatic, add tests
* add missing file
* Integrations: Support raw new lines in the text payload
* Improve support for raw new lines in text payload
The regexp used to escape control characters now also searches for
additional fields:
text|fallback|pretext|author_name|title|value