[MPIR-263] Add parameter 'targetJavaVersion' and inject ${maven.compiler.target}

No need to provide a property for targetJavaVersion. It simply does not make sense to provide that information via command line or by property means.

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1642237 13f79535-47bb-0310-9956-ffa450edef68
updated parent pom

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1642247 13f79535-47bb-0310-9956-ffa450edef68
updated parent pom and fixed errors reported by Checkstyle

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1642248 13f79535-47bb-0310-9956-ffa450edef68