QPID-5358: Checksum not implemented in record tail, not checked during read. Implemented the Alder-32 algorithm to check every record from the start of the header to the start of the record tail. Upon recovery, the recovered record checksum is compared to the record tail checksum. This should detect the condition where a multi-page record may have its header and tail written, but one or more of its inbetween pages may not be fully written.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1547601 13f79535-47bb-0310-9956-ffa450edef68