Documentation and spelling improvements

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1642128 13f79535-47bb-0310-9956-ffa450edef68
Use correct naming for Subversion and Git

GIT => Git
SVN => Subversion

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1642145 13f79535-47bb-0310-9956-ffa450edef68
Fix Checkstyle errors

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1642147 13f79535-47bb-0310-9956-ffa450edef68
[MPIR-311] Specific SCM intro is missing if dev connection is given but not anonymous connection

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1642157 13f79535-47bb-0310-9956-ffa450edef68