Build definition moved into a scala format 

This patch contain the following changes:
 * removed the content of build.sbt 
 * moved to scala 2.10.0
 * added project/ReactiveMongo.scala for build definition
 * dependencies are ready for cross version build 
 * this new build definition contain as option 
  * code auto format 
  * Publish definition in order to push the builds to oss.sonatype.org repository