Modify build for scala 2.10 and for uploading to Sonatype OSS repo.

Hello Muhammad,

I'm interested in using your Scalastyle plugin for Gradle, and made some updates to compile it with scala 2.10. I also added some things to build.gradle to make it possible to push to Maven Central, although there's a certain amount of procedure around that which I haven't undertaken yet. (There's a good article here: http://jedicoder.blogspot.com/2011/11/automated-gradle-project-deployment-to.html .)

Let me know if you have any questions about this pull request.

Thanks!

Paul