cowdb--done but not finished; CowDBMS

Release cowdb0.8.11 should come out today. It includes the last major feature--integration of deep copies, symbolic links and the changeKey operation. Now a symbolic link still does not require a referent--you can have a dangling symbolic link. But if a link references an object and the pathname of the object changes, then the symbolic link is updated to refer to the object with its new pathname. The trick here of course was to keep it fast, and it is. Deep copies and key changes take order n time, where n is the number of symbolic links that are directly impacted.

CowDb then is done. But it is rough. It needs polishing and more testing. I've also decided that the next product in this series is not the retrodictive database, but rather the Cow DBMS. In CowDBMS we will introduce some organizational structures, folders and calendars, and move a bit further away from simple tree structures.