DDL Export XSLT files need to be upgraded/improved

After working import issue TEIIDDES-215, it's become apparent that our XSLT's for various DB's need to be revisited.

For instance, there is no logic in PostgreSQL version to check for integer types that have AUTOINCREMENT == TRUE. These should be exported as SERIAL datatypes. Same for BIGSERIAL.

There is other missing logic.

We need to:

1) Create a doc or series of docs describing what datatype conversions should be done on IMPORT JDBC and EXPORT DDL
2) Create sub-tasks for implementing these docs for all DB's
3) Possibly create extension point(s) to handle "new" DB types more effeciently