[UIMA-3859] Better maven-plugin-plugin configuration

git-svn-id: https://svn.apache.org/repos/asf/uima/uimafit/branches/2.1.x@1600420 13f79535-47bb-0310-9956-ffa450edef68
[UIMA-3854] Update migration section in documentation
- Fixed some typos


git-svn-id: https://svn.apache.org/repos/asf/uima/uimafit/branches/2.1.x@1600422 13f79535-47bb-0310-9956-ffa450edef68