Added APPEND to description types,

- Added the APPEND description type
- TableEntityRefs now know their description type
- Determiner application should skip APPEND typed table entity refs
- Added DATETIME datatype, prepend and append description types where
needed in the ER diagram.
- Added appended attribute to department number. Added prepend to
project name. Determiner is now not applied when targeting a table
entity appended by a describing attribute.  Closes #19
- Added IssuesTest to focus in on the problem queries