uncommons 1.2.2 depends on jfreechart 1.0.8 not present on maven central; see:
https://github.com/dwdyer/uncommons-maths/issues/14
need specific exclusion to allow clean room build
Merge pull request #16426 from carrot-garden/sample-osgi-dining-hakkers-uncommons-pom-xml

uncommons 1.2.2 depends on jfreechart 1.0.8 not present on maven central
apply review 1
resolve akka-sample-osgi-dining-hakkers: build depends on missing artifact #16368
osgi: import sigar package as optional
introduce metrics extension
apply review 2
use kamon sigar-loader