Darrell Jones, convicted of a 1985 murder he has long contended he didn’t commit, was greeted by family and friends in Brockton on Thursday after being released from prison on $5,000 bail. Jones, 50, was granted a new trial because of possible racial bias among the all-white jury in 1986. “I stayed in prison a long time,’’ he said. “It was hard to get people to hear you.’’ B1.