Added some gda_parse_formatted_*() functions to helps parsing date and time strings
PostgreSQL: adapt to date format changes

which can be triggered by commands like "SET DATESTYLE TO..."
Oracle: some corrections
SQLite: corrected gda_sqlite_provider_get_data_handler()
Added gda_connection_get_date_format()
GdaDataModel to string: better handle date formatting
GdaSql: better handle date formatting
Misc. corrections
JDBC: SqlServer related corrections