Use sbt-release for maven style publishing

there is probably more to be added to the pom, however with this change you can execute:

sbt ";project core; release; project standalone; release" to publish those two projects, it'll prompt you a few things, probably increment the version number after core, so you'll have to set it back for stand-alone, etc.

The alternative is to add publish-settings to the default build setting, in which case all 4 projects are published...  Not sure if we want that either.

it should be obvious that the repo and credentials are just sonatype oss downloaded and temporary ran locally.  Not useful anywhere meaningful.