CLI version

Self explanatory.  

Prints the implementation version in the jar, but obviously that only works if you're running it from a jar.  Also prints the Java home and version.

Looks like: 

```
$ ./bin/doss.sh version
DOSS 2 version 0.21.0-SNAPSHOT
Java version: 1.7.0_25, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk1.7.0_25.jdk/Contents/Home/jre

For more usage: help <command>
```