Bump to 0.17.0

Minor, not patch, and the pre-1.0 rule is why: minor is this estate's breaking-change signal, and the text formatter's output IS a breaking change for anything that parses these logs. Field values and keys that contain a space, an =, a quote, a backslash, a control character or a Unicode separator are now quoted and escaped rather than written raw.

Nothing consumes these logs mechanically today as far as I could check, and I checked only slate: grepping it for =-splitting, logfmt, or log-line parsing returns one hit and it is argv parsing in main.sgl. The bump is about what the version NUMBER promises, not about a known broken consumer.

sigil.lock is untouched: it carries entries for sigil-stdlib and sigil-json, not for this package's own version.