Refactor build and release process

Copy github.com/spotify/helios build+release process.

* Use '${revision} in pom.xml and find/replace at build time.
* Automatically sign and release for sonatype.
* Add script for Jenkins to archive artifacts.
* Execute findbugs on reporting stage instead of build.
Merge pull request #33 from spotify/dxia/cd-pipe

Refactor build and release process to be like helios