683e2bf059
In preparation for a follow on change that will require checking every time a new summary is added to the SummaryList for a GUID, make the SummaryList private and require all accesses to go through one of two new interfaces. Most changes are to access the list via the read only getSummaryList() method, and the few that add new summaries (e.g. while building the combined summary) use the new addSummary() method.