Initial DefaultRecord implementation. This commit implied a reorganization of DefaultRecortType internal
for making it more convenient to DefaultRecord. We also tried to make implementations Serializable, but
DefaultRecordSchema appears to be a blocking point (difficult to make it Serializable in a reliable way).


git-svn-id: https://svn.apache.org/repos/asf/sis/branches/JDK8@1608957 13f79535-47bb-0310-9956-ffa450edef68