Implemented the ability to specify file permissions

This is the implementation of #12, allowing developers to specify the permissions of the files in the built RPM.

We have switched the integration testing language to BeanShell as we were having trouble getting the Groovy scripts working.

To implement this we had to use a newer version of Redline, which has now been published to Maven Central.

Please note we also increased the version of this plugin.
You could compile the Pattern once and keep it in a static, and then reuse it to make each matcher here.