Extension to the DSD parser to allow us to import other DSDs.
Since this generates slightly different classes, the PoemDatabase tables
and objects have been regenerated
639 lines of code changed in 7 files:
src/main/java/org/melati/poem/prepro:
DSD.java (+174 -33),
FieldDef.java (+3 -7),
HiddenTableException.java (new 61),
ReferenceFieldDef.java (+11 -8),
TableDef.java (+79 -94),
TableNamingInfo.java (new 214),
TableNamingStore.java (new 97)