Add sqlite3 exceptions to global namespace

     logging.info("falling back to sqlite3 in the standard library")
     import sqlite3
 
-__all__ = ["db"]
+__all__ = ["IntegrityError", "OperationalError", "ProgrammingError", "db"]
+
+IntegrityError = sqlite3.IntegrityError
+OperationalError = sqlite3.OperationalError
+ProgrammingError = sqlite3.ProgrammingError
 
 
 # TODO register and handle JSON type