Send output of combine_tessdata -d to stdout instead of stderr. Fixes #4149

[tfmorris]

Fixes #4149.

Rather than sending the listing to stderr send it to stdout like is done for the network listing.

Also document the hidden -ld and -dl switch combos in the help message.

[zdenop]

Thanks. In this context it would nice to finalize related issue #3998 and PR #4020

[tfmorris]

Thanks for merging. I'm not sure what's wrong with the macOS test. It ran almost 6 hours before being killed. Whatever the problem was, it clearly wasn't anything to do with this PR.

In this context it would nice to finalize related issue #3998 and PR #4020

I think this case was a little more clear cut because it was the actual requested output which was being sent to stderr. I think distinguishing between levels of logging messages (debug, info, warn, error) as far as where they get sent is less clear. I don't use training enough to argue one way or the other.