Update graphics/{ksnip,kimageannotator} to latest upstream release

Release notes are at
https://github.com/ksnip/ksnip/releases/tag/v1.8.2 (app)
https://github.com/ksnip/kImageAnnotator/releases/tag/v0.4.2 (lib)

Straightforward bugfixes, mostly.

Reported by: portscout