fixed : https://jira.codehaus.org/browse/ACT-1731

Binary variables fetched with task now get loaded in-context
like this :
task
processInstance
historicTaskInstance

备注: 将官方未解决的 有关 task processInstance historicTaskInstance 获取includeVariables 的变量 出现,拦截器外调用,报空指针异常的问题.