Add "-deprecattion" flag to metabuild
Add "-deprecattion" flag to metabuild

Fixes #2783
Ref #2716

`build.sbt` is treated a Scala source of metabuild, so to enable
deprecation flag on build.sbt we set the option here.

mdedetrich/sbt,mdedetrich/sbt,Duhemm/sbt,mdedetrich/sbt,mdedetrich/sbt,sbt/sbt,xuwei-k/xsbt,sbt/sbt,sbt/sbt,sbt/sbt,sbt/sbt,xuwei-k/xsbt,xuwei-k/xsbt,sbt/sbt,Duhemm/sbt,xuwei-k/xsbt,mdedetrich/sbt,mdedetrich/sbt,sbt/sbt,mdedetrich/sbt,xuwei-k/xsbt