SPRINGFIELD — Workers’ compensation changes central to Gov. Bruce Rauner’s “turnaround agenda” were turned away Wednesday by Senate Democrats.In a tense hearing, the Senate Judiciary Committee rejected the Republican governor’s proposal to raise the causation standard, limit claims by traveling employees and limit guidelines used to determine injury awards.The 8-4 vote along party lines came after more than two hours of debate, with the committee’s chairman alluding to slavery …