Revision 1638

Implement saving a session with a postgis connection

* Resources/XML/thuban-0.9.dtd (dbconnection, dbshapesource) New
elements for database connections and shapestores using db
connections
(session): Add the dbconnections to the content model

* Thuban/Model/save.py (SessionSaver.write_db_connections): New.
Write the db connections
(SessionSaver.write_session): Call write_db_connections to write
the connection before the data sources
(SessionSaver.write_data_containers): Handle postgis shapestores

* test/test_save.py (SaveSessionTest.thubanids)
(SaveSessionTest.thubanidrefs): Update for new DTD
(SaveSessionTest.test_save_postgis): New. Test saving a session
with postgis connections

* Thuban/Model/postgisdb.py (PostGISTable.DBConnection)
(PostGISTable.TableName): New accessor methods for the connection
and table name

* test/test_postgis_db.py (TestPostGISTable.test_dbconn)
(TestPostGISTable.test_dbname): New methods to test the new
PostGISConnection methods