[SYNCOPE-143] maven directory got from environment variable M2_HOME (empty if not set)

git-svn-id: https://svn.apache.org/repos/asf/syncope/branches/1_2_X@1625931 13f79535-47bb-0310-9956-ffa450edef68
[SYNCOPE-143] Merge from branch 1_2_X

git-svn-id: https://svn.apache.org/repos/asf/syncope/trunk@1625932 13f79535-47bb-0310-9956-ffa450edef68