STANBOL-1218: Co-Mention engine now uses -20 as default ordering in the 0.12 releasing branch

git-svn-id: https://svn.apache.org/repos/asf/stanbol/branches/release-0.12@1544514 13f79535-47bb-0310-9956-ffa450edef68
implementation of STANBOL-1219 for the 0.12 releasing branch

git-svn-id: https://svn.apache.org/repos/asf/stanbol/branches/release-0.12@1544957 13f79535-47bb-0310-9956-ffa450edef68