958a7d9315
- Use 'null' as indicator of non-MPP version. Consequently, remove useless 'isMpp' method, and lift all methods to extensions (to be able to call them on nullable 'facetSettings.mppVersion') - Change semantics of extensions to check for exact equality rather than for "at least specified version" - Deprecate old MPP-versioning in favour of 'facetSettings.mppVersion'