[STORM-2893] fix storm distribution build by using POSIX tar
[STORM-2893] fix storm distribution build by using POSIX tar

There is a known issue with the maven-assembly-plugin version 2.5+ where it fails with errors like the following:

```
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-assembly-plugin:2.6:single (default) on project final-package: Execution default of goal org.apache.maven.plugins:maven-assembly-plugin:2.6:single failed: group id '906175167' is too big ( > 2097151 ). Use STAR or POSIX extensions to overcome this limit -> [Help 1]
```

This became an issue with change 84a4314d96b9e4e377a3d5d81d0a042d96a0625e when the maven-assembly-plugin
was upgraded from version 2.2.2 to 2.6, as inherited from the apache pom version 18.

To fix this we set the assembly plugin's `tarLongFileMode` configuration setting to `posix`.

erikdw/storm,hmcl/storm-apache,hmcc/storm,hmcl/storm-apache,kishorvpatil/incubator-storm,srdo/storm,erikdw/storm,srishtyagrawal/storm,hmcc/storm,hmcc/storm,kishorvpatil/incubator-storm,hmcc/storm,hmcl/storm-apache,erikdw/storm,srishtyagrawal/storm,kishorvpatil/incubator-storm,srishtyagrawal/storm,hmcc/storm,hmcc/storm,hmcc/storm,srishtyagrawal/storm,srdo/storm,srdo/storm,srdo/storm,kishorvpatil/incubator-storm,srishtyagrawal/storm,hmcl/storm-apache,erikdw/storm,srishtyagrawal/storm,kishorvpatil/incubator-storm,hmcl/storm-apache,srdo/storm,srishtyagrawal/storm,hmcl/storm-apache,kishorvpatil/incubator-storm,erikdw/storm,hmcl/storm-apache,erikdw/storm,kishorvpatil/incubator-storm,srdo/storm,srdo/storm,erikdw/storm