Remove redundant finalize methods from the following classes:

com.arjuna.ats.arjuna.common.Mutex.java
com.arjuna.ats.arjuna.coordinator.RecordList.java
com.arjuna.ats.arjuna.coordinator.ActionHierarchy.java
com.arjuna.ats.internal.arjuna.coordinator.ReaperElement.java
com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple.java

and document their removal in the relevant release notes.