Added customData field in Xflow operator "info" parameter.
Added customData field in Xflow operator "info" parameter.

This field can be used by operators to store a state that will be preserved
on consequtive executions - as long as the child dataflow structure does not change.

Fiware/webui.Xml3d.js,xml3d/xml3d.js,CCLDESTY/xml3d.js,CCLDESTY/xml3d.js,Fiware/webui.Xml3d.js,xml3d/xml3d.js,ariyapour/xml3d.js,ariyapour/xml3d.js