* reduce diffexecutor constraints for new (so it may be used in a manager-less environment)
* add differential observers
* finish differential observeration
* requirement for observers (weak), default impl for time observer
* make the map swapper, revisit how differentialobserver is implemented
* semi-specialise multimap, add example
* improve example slightly
* fix clippy lints
* fix last clippy issue
* better docs + example flow
* improve example: correct map sizing + multimap vs split slice
* correct some comments
* fix tests + slight bit more docs
* fix bindings
* fixups for the CI
* typo fix
Co-authored-by: Dominik Maier <domenukk@gmail.com>
Co-authored-by: Dominik Maier <dmnk@google.com>
