[MPLUGIN-279] added IT with quite complete scenarios and fixed algorithm

git-svn-id: https://svn.apache.org/repos/asf/maven/plugin-tools/trunk@1645468 13f79535-47bb-0310-9956-ffa450edef68
removed dead code

git-svn-id: https://svn.apache.org/repos/asf/maven/plugin-tools/trunk@1645470 13f79535-47bb-0310-9956-ffa450edef68
[MPLUGIN-280] removed obsolete xdoc goal since it was superceeded by report goal/report

git-svn-id: https://svn.apache.org/repos/asf/maven/plugin-tools/trunk@1645484 13f79535-47bb-0310-9956-ffa450edef68