Add info output function (for unified text prompts under Heads)

[tlaurion]

We have die and warn which #1482 unifies screen output.

Everywhere in code, we seem to use echo "+++ Blah blah" as info. There is also +++++++" and variations on that. We could unify those and replicate warn and die, but without sleep calls

I suggest that we unify the codebase by adding non-sleeping info function which would prepend all text output with +++ blah (with a space) to make it clear what output comes from Heads and what comes from tools Heads uses.

Example

@JonathonHall-Purism