Add ASYN_TRACE_INFO

[tboegi]

In case that the traces ASYN_TRACE_FLOW or ASYN_TRACEIO_DRIVER
are too spammy, add ASYN_TRACE_INFO

This can be used to trace commands send to a device like a motor,
or selective status changes.

[ulrikpedersen]

Hi @tboegi

I think its a good idea to add another trace flag - we sometimes end up adding an extra custom trace flag like this for specific drivers anyway. However, your patch is lacking a few bits before it is really useful - mainly the bits that lets us control it through the asynRecord.

FYI a similar flag (ASYN_TRACE_WARNING) was added in June 2013. The tech-talk discussion is here. If you have a look at the history of that series of commits you can see how the flag was added to the asynRecord. The relevant changes start from commit b605da8

[tboegi]

I realize 3 problems:

1. The repo from the PR does not exist any more
2. The "INFO" was too confusing
3. I don't have any of EDM, MEDM or whatever UI tools available.

However, 1) and 2) are addressed here:
#63

[tboegi]

See #63