Use maven-invoker lib instead of maven command with runtime exec lib + refactoring #SYNCOPE-526

git-svn-id: https://svn.apache.org/repos/asf/syncope/branches/1_2_X@1615110 13f79535-47bb-0310-9956-ffa450edef68
[SYNCOPE-537] Deleted unnecessary underscore to comply with GuardedString of 1.4.0.0 connid version

git-svn-id: https://svn.apache.org/repos/asf/syncope/branches/1_2_X@1615502 13f79535-47bb-0310-9956-ffa450edef68
merge from branch 1_2_X

git-svn-id: https://svn.apache.org/repos/asf/syncope/trunk@1615514 13f79535-47bb-0310-9956-ffa450edef68