Added some basic documentation to the DatabaseDesign interface and added .getDatabase() and .getDocument() methods to the RichTextDoclink class
Merge remote-tracking branch 'origin/jesse' into nathan
THAT BLAST CAME FROM THE FORMULA PARSER! THAT THING'S OPERATIONAL!

Added deprecation annotations for old DbDirectory methods
Added better shielding for Database.open() when database is already open (does a log level of FINE if you really want it to)
Added Session.getMailDatabase() for completeness
Deprecated DatabaseIterator, since the DbDirectory now caches the database metadata.