Feature/use sbt and bintray for building

improving the build process
* use sbt 0.13
* use sbt-release for releasing
* use sbt-bintray for publishing the artifacts

I know that you would prefer sonatype for publishing but we can start with bintray and see after how to do

What about using the standard src tree ? Would help for contributions

I still need to :
- [ ] fix the read me
- [ ] ...