Avian UX Upgrade: Artifact Publishing

This is the first of many steps into delivering an easier-to-use Avian developer experience. I'm approaching this slowly and incrementally and trying to solve ReadyTalk's native client use case first.

In this first pull request I'm soliciting comments mainly from @dougborg, @stormbeta, @joshuawarner32, and @dicej. With the added Gradle build, I'm trying to show the logic that can be easily expanded to publish important Avian artifacts for every platform/architecture we support.

The first pass I'm only publishing linux x86_64 artifacts to: http://oss.jfrog.org/simple/oss-snapshot-local/com/readytalk/avian-linux-x86_64/

Please let me know if you like how artifacts are organized, if I'm missing important artifacts, etc. (keep in mind my intended scope mentioned above).