Review: remove stray stderr outputs

Removed a couple unguarded outputs to std::cerr, as well as many commented-out and no longer needed status outputs.

Note that there are still some uses of std::cerr, but it's my belief that they only exist in #ifdef DEBUG kinds of situations.

The general rule is that our *libraries* should never output to stdout or stderr, except for DEBUG mode.  All errors should be bubbled up via the approved error reporting methods error/geterror, etc.

Binaries specifically meant to be run on the command line, such as iinfo, may use stdout and stderr per usual conventions for command line utilities.