- session.refresh() raises an informative error message if

- session.refresh() raises an informative error message if
the list of attributes does not include any column-based
attributes.

- query() raises an informative error message if no columns
or mappers are specified.

- lazy loaders now trigger autoflush before proceeding.  This
allows expire() of a collection or scalar relation to
function properly in the context of autoflush.

- whitespace fix to new Table prefixes option