Process settings once in SettingGraph for better performance.
Process settings once in SettingGraph for better performance.

Running 'inspect tree sbt/update' on sbt goes from 27 s to <1 s.
Review by @eed3si9n.

sbt/sbt,twitter-forks/sbt,sbt/sbt,pdalpra/sbt,mdedetrich/sbt,xuwei-k/xsbt,mdedetrich/sbt,xuwei-k/xsbt,xuwei-k/xsbt,sbt/sbt,pocketberserker/sbt,xeno-by/old-scalameta-sbt,mdedetrich/sbt,mdedetrich/sbt,jaceklaskowski/sbt,xuwei-k/xsbt,jaceklaskowski/sbt,jkinkead/sbt,dyx/sbt,twitter-forks/sbt,sbt/sbt,jaceklaskowski/sbt,dyx/sbt,sbt/sbt,xeno-by/old-scalameta-sbt,dyx/sbt,mdedetrich/sbt,mdedetrich/sbt,Duhemm/sbt,jkinkead/sbt,xuwei-k/xsbt,xeno-by/old-scalameta-sbt,jaceklaskowski/sbt,som-snytt/xsbt,adriaanm/sbt,xeno-by/old-scalameta-sbt,jkinkead/sbt,corespring/sbt,jaceklaskowski/sbt,jkinkead/sbt,twitter-forks/sbt,Duhemm/sbt,sbt/sbt,mdedetrich/sbt,jkinkead/sbt,twitter-forks/sbt,Duhemm/compiler-bridge,dansanduleac/sbt,xeno-by/old-scalameta-sbt,twitter-forks/sbt,jasonchaffee/sbt,dyx/sbt,dyx/sbt,Sciss/sbt,sbt/sbt,xeno-by/old-scalameta-sbt