More than 100 teachers and care workers convicted of child abuse could now have their cases re-investigated. Today, a former care worker jailed for abusing children more than 20 years ago had his conviction quashed as unsafe. Anver Sheikh had served two years of an eight-year sentence, and will now be released on bail while judges decide next month if he should face a retrial. Lawyers say many of the convictions hinge on the credibility of the witnesses. The Criminal Cases Review Commission says it expects some of the cases will be referred to them…..