TMDM-7711: init fix on overlapped x-axis labels

TMDM-7711: code refactoring

TMDM-7711: final fix on long names overlapping issue (JournalChart portlet)

TMDM-7711: fix for x-axis labels overlapping for RoutingChart and minor adjustment for totalLength of all the potential lables

TMDM-7711: minor code refactoring

TMDM-7711: show tool-tip like info for entities in data chart

TMDM-7711: rotating axis labels for DM with many entities.

1. revert original workaround (for gflot-3.2.2, no rotating label features)
2. use rotating feature in new gflot version
Merge branch 'maintenance/5.6'