Mahout-1207: Fix typos in description in parent pom

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1481556 13f79535-47bb-0310-9956-ffa450edef68
Mahout-1207: DRY out maven-compiler-plugin configuration

git-svn-id: https://svn.apache.org/repos/asf/mahout/trunk@1481564 13f79535-47bb-0310-9956-ffa450edef68