Specific support for DocumentSummaryInformation, SummaryInformation types.

Support classes for "well-known" section format IDs and property IDs. The streams `\005DocumentSummaryInformation` and `\005SummaryInformation` (or any streams with the same section format IDs as the aforementioned) are considered well-known. So are most property IDs in these streams.

@author Rainer Klute (klute@rainer-klute.de) @version $Id$ @since 2002-02-09