Uses graph editor component from DREAM simulation project http://dream-simulation.eu/

This editor is in early stage; it supports edition of business paths from business process and edition of workflow layout in DCWorkflow.

Known problems / TODO:
 - DCWorkflow editor only saves the graph layout and does not allow designing the workflow
 - DCWorkflow graph has to be enabled in history tab for history visualisation
 - rendering of fields in the property edition dialog is extremely slow
 - mixin_promise.js have to be merged. Other TODO's in test.js and jsplumb.js. Generally speaking, this javascript code is poor quality