Would be nice to have a way to eliminate informative stdout messages, and get error information programmatically

[nosuchtim]

Two related issues.

Currently, senselGetDeviceList (and possibly other APIs) send informative messages to stdout. It would be nice to be able to turn those off, for a variety of reasons (e.g. running inside a plugin, or utilities that want to be silent except for errors).

Error messages are currently sent to stdout, and in some cases different errors producing the same API return value (SENSEL_ERROR) without a way for the caller to find out which error occurred. At the very least it would be nice for there to be a few other ERROR types, and ideally the error messages themselves should be retrievable programmatically rather than being unconditionally printed.