Fix issue2551029 (Jinja2 template install error) by deleting config.ini from all templates. Looks like classic and minimal never included a config.ini. Presence of config.ini stopped 'roundup-admin install' from generating an up to date config.ini. Created special option class for backend database. Comment now uses roundup.backend.list_backends to give user indication of valid values. Also we now get an error if user specifies invalid backend. Moved backend setting to top or [rdbms] section. It is the most important thing in there and if set to anydbm (or some other non-rdbm) the rest of the settings can be ignored. Change rdbms config section comment to indicate that the backend setting was used by other database backends. (e.g. if set to anydbm).

roundup.anypy package - Python version compatibility layer
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Roundup currently supports Python 2.3 to 2.6; however, some modules
have been introduced, while others have been deprecated.  The modules
in this package provide the functionalities which are used by Roundup

- adapting the most recent Python usage
- using new built-in functionality
- avoiding deprecation warnings

Use the modules in this package to preserve Roundup's compatibility.

# vim: si