WHISKER-12: MavenPluginErrors again

- Followed instructions from http://maven.apache.org/plugin-tools/maven-plugin-plugin/examples/using-annotations.html to get rid of the mojo error.
- Extracted version number of mavenPluginPlugin, use it for maven-annotations as well to keep these dependencies in sync.



git-svn-id: https://svn.apache.org/repos/asf/creadur/whisker/trunk@1619935 13f79535-47bb-0310-9956-ffa450edef68