change deploy tool to detect current stratosphere version

 and dynamically generate the yarn build.

This should be merged before https://github.com/stratosphere/stratosphere/pull/219

This is how the tools builds the versions:
```
robert@robert-tower ~/Projekte/ozone/ozone (git)-[fix_deploy_tool] % ./tools/deploy_to_maven.sh
detected current version as: 0.4-SNAPSHOT ; yarn: 0.4-hadoop2-SNAPSHOT 
robert@robert-tower ~/Projekte/ozone/ozone (git)-[fix_deploy_tool] % ./tools/deploy_to_maven.sh
detected current version as: 0.4-alpta.2 ; yarn: 0.4-alpta.2-hadoop2 
```