Remove all direct printing to stdout and stderr.

A library should never, ever print anything directly to stdout/stderr unless explicitly requested to do so, as it may be linked with programs that need to control what they output to stdout/err or programs that have no stdout/err at all.

Failures should be raised via the API error mechanism with appropriate message strings that the caller can display as they see fit. Informational log messages should be logged in a way that the caller can send them where they want or turn them off if they want.